Flexible and Biocompatible Supercapacitors for Biomedical Application

Sachdev N and Biswas S

Published on: 2025-11-24

Abstract

Biomedical equipment, including pacemakers, neural stimulators, and wearable health monitoring, require secure, compact, and biocompatible power sources. Traditional lithium-ion batteries, despite their prevalent application, are constrained by inflexible form factors, limited cycle longevity, dangers of electrolyte leakage, and sluggish charge-discharge rates, hence impeding their appropriateness for flexible and implantable systems. Flexible supercapacitors (FSCs) have emerged as appealing alternatives owing to their elevated power density, quick charging capabilities, prolonged cycling stability, and mechanical versatility. When integrated with biocompatible electrode and electrolyte materials, these devices offer dependable energy storage capable of functioning safely in physiological conditions. This review emphasizes current advancements in flexible biocompatible supercapacitors (BMSCs), concentrating on carbon-based nanostructures, conductive polymers, hydrogels, and hybrid composites. It also analyses device configurations including thin films, fiber-based designs, micro-supercapacitors, and hybrid electrochemical systems specifically designed for biomedical applications. Ultimately, future prospects are examined, encompassing biodegradable platforms, self-sustaining systems, and multifunctional gadgets that amalgamate sensing with energy storage. Collectively, these advancements establish BMSCs as a revolutionary alternative for energizing next-generation biomedical electronics.

Keywords

Biocompatible supercapacitors; Flexible supercapacitors

Introduction

Biomedical equipment, including pacemakers, brain implants, biosensors, and wearable health patches, increasingly require secure, compact, and biocompatible power sources. Conventional lithium-ion batteries are the prevailing option; nevertheless, their inflexible packaging, potential for leakage, restricted flexibility, and comparatively sluggish charge-discharge kinetics hinder their incorporation into conformal and implantable systems. Flexible supercapacitors (FSCs) have emerged as viable alternatives owing to their elevated power density, swift charging capacity, mechanical pliability, and compatibility with soft substrates. In contrast to batteries, FSCs accumulate energy via electrical double-layer capacitance and pseudo capacitance, facilitating charge-discharge durations of only seconds and cycle life spans frequently surpassing tens of thousands of cycles. Kirigami inspired MnO2 nanowire FSCs retained 98% capacitance after 10,000 cycles at 400% strain, illustrating its durability under high deformation [1]. Asymmetric graphene-based flexible supercapacitors have attained power densities reaching 23.3 kW kg?¹ [2].

Recent advancements further illustrate that FSCs can compete with or even exceed the energy density of micro batteries. Conductive polymer-hydrogel hybrid electrodes demonstrated areal capacitances of 885 mF cm?² and stretchability of up to 800% [3]. Stretchable transparent flexible supercapacitors (FSCs) designed for implanted devices exhibited capacitances of 15.02 mF cm?², alongside exceptional mechanical robustness and optical transparency, rendering them appropriate for advanced bioelectronics [4]. Similarly, liquid-metal-integrated flexible supercapacitors incorporated within elastomers have attained volumetric energy densities of 25 mWh cm?³ and power densities of 32 W cm?³, meeting the specifications for epidermal and implantable electronics [5].

Recent developments in the design and use of wearable, flexible supercapacitors for physiological and biomedical monitoring are depicted in Figure 1. Panel A shows how graphene/carbon nanofiber (GE/CNF) composites are made by vacuum drying and hydroiodic acid reduction, producing extremely flexible, waivable structures with superior electrochemical performance and stability. The potential for real-time, body-mounted sensing is demonstrated by the electrochemical signals captured from various body locations (forehead, arm, and finger) and the accompanying thermal images. Panel B displays a skin-attachable supercapacitor patch made of self-supporting carbon nanostructures that can generate a steady current while the neck moves, demonstrating both sensitivity and mechanical adaptability. A sustainable lignin-derived micro supercapacitor (MSC) with carbon nanotubes (CNTs) incorporated, created by laser writing, is shown in Panel C. It has many sensing functions for body motion, pressure, and humidity. The gadget effectively tracks a variety of human motions, such as bending, swallowing, winking, yawning, and clenching, confirming its promise as a biosensing and energy storage platform of the future. Together, the figure highlights mechanical flexibility, multifunctionality, and scalable fabrication, establishing these wearable supercapacitors as viable options for applications involving human-machine interfaces and healthcare [6].

Figure 1: Recent Developments in Wearable and Flexible Supercapacitors Include: (A) Waivable Devices Based on Graphene/Carbon Nanofibers that Exhibit Stable Electrochemical Performance for Body-Mounted Monitoring; (B) A Skin-Attachable Supercapacitor Patch that Exhibits Mechanical Adaptability and Dependable Current Output; and (C) Micro supercapacitors Made of Lignin that are Integrated with Carbon Nanotubes for Multipurpose Sensing of Physiological Activities and Human Motions [6].

This review emphasizes cutting-edge materials, device designs, and biomedical applications of flexible biocompatible supercapacitors (BMSCs). Significant advancements have been made in carbon nanostructures, conducting polymers, hydrogels, and hybrid electrodes, as well as in system-level designs including thin-film, fiber, and micro-supercapacitors with stretchy and transparent configurations. Significant obstacles persist, such as enduring electrochemical stability in physiological conditions, scalable downsizing, and integration with multifunctional biomedical systems. Future prospects indicate that biodegradable, self-healing, and self-powered BMSCs will serve as sustainable and secure energy storage solutions for next-generation biomedical devices [6,7].

Material Strategies

The efficacy of flexible biocompatible supercapacitors (BMSCs) is mostly determined by the selection of electrode and electrolyte materials. Essential design factors encompass elevated capacitance, mechanical flexibility, electrochemical stability in biological settings, and prolonged biocompatibility. We summarize recent advancements in four principal categories of materials: carbon-based nanostructures, conducting polymers, hydrogels/biomaterials, and metal oxides/nitrides alongside their quantitative performance measurements.

Carbon-Based Nanostructures

Carbon nanomaterials, particularly carbon nanotube (CNT) fibers and graphene, are crucial for the development of flexible and biocompatible supercapacitors, owing to their outstanding electrical conductivity, great chemical stability, and exceptional mechanical strength. These materials provide a highly conductive framework that enables efficient charge transport while maintaining structural flexibility, making them especially suitable for integration into bioelectronics where performance and adaptability are crucial. Carbon nanotube fibers have been extensively studied within biological environments. Their electrochemical stability in biofluids, such as phosphate-buffered saline (PBS) and blood, has been effectively confirmed. CNT fiber-based supercapacitors achieved areal capacitances of over 20 mF cm?², exhibiting stable performance for over 10,000 cycles in PBS while maintaining over 95% of their initial capacitance [8]. The results confirm the longevity of CNT fibers for extended biomedical applications, a critical attribute for implantable devices that require dependable functioning without regular replacement. CNT fibers have exceptional compatibility with flexible device architectures, enabling their integration into textiles or microscale designs without detriment to electrochemical performance. Recent advancements illustrate multifunctionality; for example, CNT yarn supercapacitors have been designed to simultaneously store energy and monitor reactive oxygen species in real time, facilitating dual functions in implantable biomedical systems [9].

Graphene nanosheets are a significant carbon nanostructure, distinguished by an extraordinary theoretical surface area of 2,600 m² g?¹, providing a vast platform for charge storage through double-layer capacitance mechanisms. When constructed into porous reduced graphene oxide (rGO) sheets, these materials achieve volumetric capacitances of approximately 60 F cm?³, demonstrating exceptional cycling stability in flexible topologies [10]. Hybrid grapheme-CNT scaffolds have enhanced electrochemical performance; for instance, porous composites have exhibited volumetric capacitances of up to 60.75 F cm?³ while maintaining mechanical flexibility [11]. These advancements bring graphene-based supercapacitors nearer to closing the energy disparity with batteries, while maintaining their exceptional safety and cycling stability. Besides electrochemical efficiency, the mechanical resilience of carbon nanostructures is essential for their biological applications. Both carbon nanotubes and graphene demonstrate remarkable resilience to mechanical deformation. Devices constructed from these materials typically retain over 90% of their capacitance after 1,000 bending cycles at radii as small as 5 mm, underscoring their ability to maintain stable performance despite repeated flexing [8]. This durability is crucial for implantable and wearable devices that must conform to soft tissues or dynamic body movements without mechanical or electrochemical breakdown. Moreover, the surface modification of carbon nanotubes and graphene, through the incorporation of biopolymers or hydrophilic groups, has shown enhancements in wettability, improved ion transport, and diminished potential cytotoxicity, thereby expanding their suitability for safe biomedical applications [12]. CNT fibers and graphene are recognized as highly adaptable materials for flexible, biocompatible supercapacitors. They offer high specific capacitance and remarkable cycling stability while also meeting the mechanical and chemical criteria for operation in physiological environments. Their continuous progress, particularly through hybridization with polymers or biomaterials, is expected to accelerate the implementation of flexible supercapacitor technology in real biomedical applications. Figure 2 shows a schematic illustration of the many uses for carbon-based composites and nanomaterials, highlighting their importance in biomedical devices. Graphene, carbon nanotubes (CNTs), activated carbon (AC), and carbon nanostructures (CN) are among the important carbon allotropes highlighted in the central framework. Each of these materials has unique chemical and physical characteristics, including high surface area, exceptional electrical conductivity, and mechanical flexibility. The medical devices industry is one of the most important fields where carbon nanomaterials have a revolutionary impact among the many applications shown. Because of their remarkable electrical conductivity, flexibility, and biocompatibility, graphene and carbon nanotube composites are used in implantable energy devices, drug delivery systems, biosensors, and scaffolds for tissue engineering. These materials are perfect for energy-assisted biomedical applications and real-time monitoring because they facilitate effective electron transfer and biological interface. All things considered, the figure highlights how versatile carbon is in enabling next-generation technologies, especially in promoting advancements in therapeutics and medical diagnostics [13].

Figure 2: Show Carbon-Based Nanomaterials Superior Electrical Conductivity, Mechanical Strength, and Biocompatibility are: used in Biomedical Devices [13].

Conducting Polymers

Conducting polymers are a crucial category of materials for flexible biocompatible supercapacitors (BMSCs) owing to their distinctive amalgamation of pseudo capacitance, mechanical flexibility, and inherent biocompatibility. In contrast to carbon nanomaterials, which predominantly store charge through electric double-layer capacitance, conducting polymers employ swift and reversible redox reactions, facilitating significantly higher capacitance values-beneficial for biomedical devices that necessitate both elevated energy density and mechanical flexibility. PANI is among the most extensively researched conducting polymers for energy storage applications. Reported specific capacitances range from 400 to 600 F g?¹, however cycling stability is frequently constrained to approximately 5,000 cycles because to mechanical deterioration resulting from volumetric alterations during redox processes [14]. Hollow PANI fibers have achieved 601 F g?¹, while structural instability persists as a limitation [15]. PPy electrodes exhibit potential due to their excellent ionic conductivity in physiological fluids. PPy-based flexible devices exhibit areal capacitances of 80-120 mF cm?², maintaining over 80% capacitance after 5,000 cycles in saline conditions, rendering them appropriate for implantable and wearable applications [16]. PEDOT: PSS. PEDOT: PSS is distinguished by its exceptional conductivity, biocompatibility, and elasticity. Flexible PEDOT: PSS films and fibers exhibit capacitances around 200 F g?¹ and may endure tensile strains of up to 100%, facilitating its application in stretchable devices [17]. Biocompatibility tests indicate negligible cytotoxicity, with fibroblast assays validating its safety for bioelectronic integration [18]. Various biomedical applications of conducting polymers are shown in Figure 3. These materials are ideal for biomedical advancements due to their electrical conductivity, biocompatibility, and mechanical flexibility. Bio actuators for muscle-like motion, hydrogels for medication delivery and tissue regeneration, neural prosthetic devices for signal transmission, and biomedical sensing devices are shown in the figure. Conducting polymers stimulate cell growth and regeneration in tissue engineering scaffolds and smart textiles for wearable health monitoring. These applications demonstrate the versatility of conducting polymers as electronics-biology materials [18].

Figure 3: Bio Actuators, Hydrogels, Neural Prosthetics, Tissue Engineering, and Smart Textiles Use Conducting Polymers' Superior Conductivity and Biocompatibility [18].

In addition to their independent uses, conducting polymers are progressively integrated with nanostructured carbons and hydrogels. PANI/graphene composites have attained capacitances of 700 F g?¹ while preserving stability for over 10,000 cycles [14]. PEDOT: PSS and PPy hydrogels offer customizable softness and hydration, essential for implantable devices [19]. Bio-derived composites, including chitosan/PPy and cellulose/PANI, have been examined for skin-contacting supercapacitors, demonstrating biodegradability and remarkable flexibility [20]. Conducting polymers are being integrated into multifunctional devices. Zhao et al. emphasized their contribution to the development of self-sustainable, flexible supercapacitors that integrate energy storage, sensing, and transparency for wearable electronics [15].

Collectively, conducting polymers like PANI, PPy, and PEDOT: PSS epitomize the forefront of BMSC research, integrating elevated pseudo capacitance with biocompatibility and flexibility. Their advancements in composites and hydrogels are propelling the next generation of secure, resilient, and multipurpose biomedical energy storage systems.

Hydrogels and Biomaterials

Hydrogels are becoming acknowledged as viable substrates for flexible and biocompatible supercapacitors (BMSCs) due to their dual functionality as electrodes and electrolytes. Their pliability, elevated water content, and adjustable porosity render them mechanically compatible with biological tissues, while their biodegradability facilitates the development of temporary and environmentally sustainable biomedical devices. A key benefit of hydrogel-based supercapacitors is their elevated ionic conductivity (10?²-10?¹ S cm?¹), which rivals that of liquid electrolytes while maintaining a stable, solid-like configuration [17]. The integration of fluidic ion transport and solid-state stability renders hydrogels highly appropriate for skin-mounted and implanted devices. Electrochemical investigations validate the significant performance potential of hydrogel supercapacitors.

A fully stretchable all-hydrogel supercapacitor utilizing PANI@rGO/MXene electrodes attained a specific capacitance of 157 F g?¹ and an energy density of 8.7 Wh kg?¹, while preserving adhesion and stability in vivo [3]. Conductive polymer hydrogels enhance both flexibility and capacitance; polyacrylamide/sodium alginate hydrogels fortified with PEDOT: PSS sustained approximately 200 F g?¹ capacitance while exhibiting stretchability surpassing 80%, illustrating their dual functions as electroactive and mechanical support matrices [17]. Redox-additive hydrogels enhance performance, achieving reported energy densities of up to 12.5 Wh kg?¹ [21]. Natural biomaterials are being included into hydrogel systems to improve sustainability. Cellulose-based hydrogel supercapacitors exhibited 50-70 F cm?³ volumetric capacitance and demonstrated 100% biodegradation in soil after 60 days, indicating potential applications in disposable and environmentally sustainable electronics [22]. Silk fibroin hydrogels serve as flexible, low-cytotoxic ionic conductors, whereas chitosan-based hydrogels demonstrate antibacterial properties and function as biodegradable separators in energy storage systems [23]. Biocompatibility is fundamental to biomedical applications. Implanted all-hydrogel supercapacitors exhibited exceptional in vivo safety; devices implanted in mice for several weeks showed no indications of inflammation or tissue damage, thereby affirming their cytocompatibility and long-term tolerance [3]. Hydrogel-based BMSCs integrate softness, biocompatibility, biodegradability, and robust electrochemical performance. Their ongoing advancement via the integration of conducting polymers, redox-active additives, and natural biomaterials establishes them as next-generation energy storage systems for skin-mounted sensors, implantable stimulators, and transient monitoring devices.

Metal Oxides and Nitrides

Transition metal oxides (TMOs) and nitrides (TMNs) have garnered considerable interest for flexible and biocompatible supercapacitors (BMSCs) owing to their inherently high theoretical capacitances, abundant redox activity, and adjustable electronic characteristics. Their specific capacitances frequently exceed those of carbon-based materials, rendering them interesting candidates for energy-dense biomedical storage devices. Nonetheless, obstacles like ion leaching and prolonged chemical stability in physiological fluids restrict their direct application in biomedicine. Titanium nitride (TiN) and niobium nitride (NbN) electrodes exhibit metallic conductivity alongside pseudocapacitive properties. Sharma et al. documented a flexible NbN||TiN asymmetric supercapacitor functioning in simulated physiological fluid, achieving approximately 150 mFcm?² areal capacitance and an energy density of approximately 12 Whkg?¹, exceeding the performance of numerous polymer-based devices [24]. Likewise, thin-film Ti?N-based devices attained elevated areal energy densities while preserving mechanical flexibility [25]. Notwithstanding this assurance, the release of metal ions during cycling continues to pose a cytotoxicity issue, necessitating protective encapsulation methods such as parylene layers, hydrogel coatings, or bio-derived polymer encapsulants. Nanostructured ZnO electrodes in flexible devices exhibit specific capacitances of 400-500 F g?¹ with excellent rate capability, owing to their elevated surface area and rapid ion transport [26]. Molybdenum oxide (MoO?) based hybrids generally achieve 500-700 F g?¹ due to their layered crystalline architecture and numerous redox-active sites. When integrated with conductive carbons or polymers, their mechanical flexibility and conductivity are markedly enhanced [27]. Tungsten nitride (WN) coated graphene fibers have been engineered, attaining elevated areal capacitance and exceptional bending stability, underscoring the adaptability of TMC-based hybrid electrodes for wearable applications [28]. Despite the strong performance of TMOs and TMNs, their instability in physiological conditions, characterized by dissolution or phase changes, poses a risk to biosafety. Recent studies indicate that encapsulating oxides in conductive hydrogels enhances ion transport while minimizing direct ion release, and surface functionalization with bio-derived polymers (e.g., alginate, silk fibroin) enhances tissue compatibility without sacrificing electrochemical performance [29].

To assess the advancement of flexible biocompatible supercapacitors, it is beneficial to compare the primary categories of electrode materials that have been investigated thus far. Carbon-based nanostructures, conducting polymers, hydrogels, biomaterials, and transition metal oxides/nitrides each offer unique benefits and drawbacks regarding energy storage efficiency, biocompatibility, and durability over time. The subsequent table encapsulates exemplary instances from the literature, emphasizing their performance metrics, biological interactions, and the obstacles that need to be surmounted for effective clinical and commercial translation.

Table 1: A Comparative Comparison of Chosen Material Systems Employed in the Production of Flexible and Biocompatible Supercapacitors, Organized by Material Type. The Table Covers Major Parameters Such as Flexibility, Biocompatibility, Capacitance, Energy Density, Cycle Life, and Noteworthy Application Aspects Based on Published Research.

Category	Material/System	Key Components	Flexibility	Biocompatibility	Capacitance	Energy Density	Cycle Life	Special Features/Applications	Citation
Metal Oxides and Nitrides	Ti?N thin-film	Di-titanium nitride on SS304	High	~85% cell viability	–	1.614 µWh/cm²	5000 cycles	Implantable, PBS stable	[30]
	NbN on Cu foam	NbN sputtered on Cu foam	High	High (no cytotoxicity)	10.772 F/g	–	5000 cycles	Operates in physiological fluids
	MoOx-based biodegradable SC	MoOx on Mo foil	High	Biodegradable (in vivo)	112.5 mF/cm²	15.64 µWh/cm²	–	Fully biodegradable, absorbed in rat body	[31]
Hydrogels and Biomaterials	Chitosan bio-composite	Chitosan/MnO?@MnCO? + IL	Good	~90% cell viability	2.5 F/cm²	0.35 Wh/cm²	~10,000 cycles	Textile-integrated, wearable	[32]
Hydrogels and Biomaterials	MXene-based ZHSC	MXene cathode + Zn anode + silk film	Excellent	High (in vivo tested)	482.58 mF/cm²	7.37 mWh/cm³	10,000 cycles	Wet-adhesive, degradable, implantable	[33]
Conducting Polymers and Carbon-Based Nanostructures	Ionic liquid–polymer composite	Conducting polymer + biopolymer + IL + graphite	High	High	~5 mF/g	–	>15,000 cycles	Ultrathin, chemically stable	[34]
	Juglone-Polypyrrole	Natural juglone + polypyrene	High	Likely High	High (not quantified)	–	Long cyclability	Green, lightweight & flexible	[35]
	Crystalline tetra-aniline (c-TANi)	c-TANi + PEG + NaCl gel	High	High	Not specified	–	Good retention post-healing	Self-healing, wearable/implantable	[36]

The comparative table shows the important attributes of materials typically utilized in the creation of flexible and biocompatible supercapacitors, which are divided into three categories: metal oxides and nitrides, hydrogels and biomaterials, and conducting polymers containing carbon nanostructures. Each category offers significant advantages for biological applications. Metal oxides and nitrides, such as Ti?N, NbN, and MoOx, have excellent electrochemical performance, mechanical flexibility, and biocompatibility. Some even offer biodegradability for implanted devices. Hydrogels and biomaterials such as chitosan composites and MXene-based designs improve device adaptation in physiological conditions by combining flexibility with high capacitance and energy density. Conducting polymers and carbon-based systems strike a balance between mechanical compliance, electrical conductivity, and self-healing properties, making them excellent for wearable or skin-conformable electronics. This organized comparison helps to guide material selection based on application-specific requirements such as energy density, mechanical performance, and biocompatibility.

Device Configurations

The architecture of flexible biocompatible supercapacitors (BMSCs) is as crucial as the choice of electrode and electrolyte materials, as device design directly affects the efficiency of energy storage units in integrating with soft, dynamic biological surroundings. In contrast to traditional rigid batteries, biomedical power sources must adapt to tissues, endure recurrent mechanical deformation, and maintain stability in fluid physiological environments. Consequently, in addition to inherent material characteristics, the structural configuration of the device determines its long-term performance, reliability, and biosafety in vivo [15]. Various configurations have been designed to enhance trade-offs among energy density, flexibility, transparency, and durability, each customized for particular biomedical applications. Thin-film devices, for instance, provide conformal integration with wound dressings or epidermal patches and have attained areal capacitances of 20-40 mF cm-2, demonstrating bending stability over 1,000 cycles [6]. Fiber-based devices offer a one-dimensional configuration suitable for textile electronics or implanted sutures. CNT-fiber supercapacitors demonstrate linear energy densities reaching 80 mWhcm-3 and maintain over 90% capacitance during repetitive flexing [37].

Micro-supercapacitors (MSCs) produced by lithographic or printing methods have gained significant appeal for miniaturized implantable bioelectronics. Wafer-scale MSCs demonstrate 10–50 mF cm-2 areal capacitance and power densities surpassing 10 mW cm-2, facilitating ultrafast charge–discharge capabilities in ultrathin devices [38]. In mechanically demanding applications, stretchy and translucent supercapacitors are essential. Elastomer based architectures exhibit tensile strain tolerance of up to 100% while preserving over 90% capacitance [39] and graphene or nano-mesh based transparent devices attain optical transmittance exceeding 80% with areal capacitances ranging from 5 to 15 mF cm-2 [40]. These characteristics render them suitable for dermal electronics and ocular devices. Figure 4 depicts the various device topologies used in flexible and biocompatible supercapacitors (BMSCs), demonstrating how diverse structural designs promote efficient energy storage and biological integration. The picture depicts six primary architectures: thin-film, fiber-based, micro-supercapacitor, stretchy, transparent, and hybrid systems, each designed for a distinct application, such as skin patches, implanted power units, electronic skin, and smart eye lenses. The fundamental concept of energy storage is linked to bio-integration, as indicated by directed arrows, stressing the dual goals of these systems: high-performance electrochemical output and physiological adaptation. Thin-film and fiber-based devices provide compactness and flexibility, whilst micro-supercapacitors attain high areal capacitance in small footprints. Stretchable and translucent systems enable next-generation wearable and implantable electronics, while hybrid designs combine capacitive and faradaic processes to increase energy density. Overall, the figure demonstrates BMSCs' structural plasticity and multifunctional potential for smooth integration into biological contexts.

Figure 4: Summary of Device Configurations in Flexible Biocompatible Supercapacitors, Emphasizing Thin-Film, Fiber-Based, Micro, Stretchable, Transparent, and Hybrid Designs for Energy Storage and Biological Integration.

Thin-Film and Fiber Devices

Thin Film and Fibre Optic Devices, Flexible supercapacitors (FSCs) based on thin films and fibers have garnered considerable interest for incorporation into biomedical textiles, wound dressings and implantable devices owing to their adaptability and mechanical strength. Fiber geometries provide inherent versatility for integration into textiles or incorporation into sutures, facilitating multifunctional biomedical systems.

Graphene/polyaniline (PANI) hybrid fibers are a highly promising category of electrode materials. Wu et al. exhibited fiber-shaped fibre supercapacitors (FSCs) utilizing graphene/polyaniline (PANI) hybrids, achieving areal capacitances of 80-120 mF cm?², with over 90% retention after 5,000 cycles in saline solutions and minimal performance degradation under repeated bending [41]. Likewise, polypyrrole (PPy) hybrid fibers have demonstrated exceptional electrochemical performance; Teng et al. reported specific capacitances surpassing 400 F g?¹ in hierarchically interconnected PPy hybrid fibres, exhibiting long-term cycle stability and robust mechanical strength [42]. Teng et al. recently developed PEDOT: PSS/rGO/PPy fiber electrodes that maintained >90% of their initial capacitance after 8,000 cycles, highlighting their durability for biomedical applications [43]. Asymmetric fiber arrangements enhance performance. Liu et al. developed Ti?C?Tx/RGO/PANI/RGO asymmetric fiber FSCs that attained 25 F cm?³ volumetric capacitance and preserved flexibility during bending without substantial degradation, rendering them appropriate for implantable and wearable devices [44]. Li et al. devised polyaniline array partially reduced graphene oxide (rGO) hybrid fibers, demonstrating a volumetric capacitance of 50.2 F cm?³ and maintaining 96.6% capacitance after 2,000 bending cycles, signifying remarkable stability for repetitive physiological movements [45]. These advancements collectively indicate that fiber-based FSCs satisfy the electrochemical requirements of biomedical devices while also fulfilling essential criteria of flexibility, miniaturization, and durability in physiological environments. Their incorporation into wearable wound dressings, bio-textiles, and implantable fibers underscores their promise as advanced biocompatible power sources.

Micro-Supercapacitors (MSCs)

Micro-supercapacitors (MSCs) have emerged as a very promising device configuration for biomedical electronics due to their integration of miniaturization, elevated power density, and scalability, which are critical for implantable and wearable medical systems. In contrast to thin-film or fiber-based devices, MSCs include interdigital or three-dimensional micro-patterned architectures on substrates, facilitating ultrathin energy storage components that occupy little space while providing superior electrochemical performance. This renders them especially appropriate for energizing microscale bioelectronics, including implanted sensors, brain stimulators, and lab-on-chip diagnostic systems.

A primary benefit of MSCs is their capacity to provide elevated areal capacitance and rapid charge-discharge performance. Wafer-scale integrated MSCs have been realized utilizing micropatterned carbon or PANI-based electrodes on flexible substrates, attaining areal energy densities of around 10 mWh cm?² and exhibiting stable performance under bending conditions [46, 47]. Advanced 3D interdigitated MSCs significantly improve performance by augmenting the surface area for charge storage, achieving areal energy densities of 1-10 mWh cm-2, which are comparable to thin-film lithium batteries while preserving the mechanical durability of supercapacitors [48].

Recent advancements have concentrated on enhancing both flexibility and biocompatibility of MSCs. Graphene and MXene-based MSCs constructed on polyimide or silk fibroin substrates exhibited areal capacitances exceeding 20 mF cm-2, with over 90% retention following 5,000 bending cycles at minimal radii (~5 mm) [49]. Likewise, biocompatible MSCs included in epidermal patches demonstrated consistent electrochemical performance in both sweat and saline, highlighting their potential for on-skin energy harvesting and storage [40].

A significant focus has been the amalgamation of MSCs with bioelectronic platforms. For instance, mesenchymal stem cells (MSCs) integrated with triboelectric nanogenerators (TENGs) have exhibited self-charging abilities, enabling devices to perpetually power small biological sensors during mechanical motion [50]. Such systems may ultimately enable completely autonomous, implantable, or wearable medical devices that do not depend on external recharging. MSCs constitute a revolutionary framework for BMSCs by providing ultrathin, miniaturized, and scalable solutions with superior electrochemical performance and integration capabilities. Their ongoing progress utilizing bio-derived substrates, encapsulation techniques, and multifunctional integration establishes them as formidable contenders for next-generation implantable bioelectronics.

Stretchable and Transparent Devices

In applications like bioelectronic skins, epidermal patches, and optical biomedical platforms like smart contact lenses, stretchability and transparency are becoming essential requirements for the next generation of biomedical supercapacitors. Devices intended for skin or ocular integration must endure repeated mechanical deformation while preserving optical clarity and biocompatibility, in contrast to traditional rigid energy storage systems. The development of wearable and implantable bioelectronics has thus turned to stretchy and transparent flexible supercapacitors (FSCs).

In order to accept substantial deformations without sacrificing electrochemical performance, stretchable devices are usually designed using elastomeric substrates (PDMS, Eco flex, etc.) or structural designs like serpentine, wavy, or mesh-like electrode patterns. They are perfect for epidermal electronics that are constantly bent and stretched by body action, as studies have shown capacitance retention of >90% under tensile strains up to 50-100% [39]. For example, carbon nanotube (CNT) elastomer composites have shown their mechanical durability and adaptability for skin-mounted power sources by demonstrating areal capacitances of 30-40 mF cm-2 while maintaining >85% performance after 5,000 stretching cycles at 50% strain [51, 52]. For applications like bio-integrated optical sensors, smart contact lenses, and eye implants, transparent devices are equally important. Because of their great optical transmittance and electrical conductivity, graphene and silver nanowire (AgNW) networks have found extensive use as transparent electrodes. Graphene film-based devices can be integrated into transparent biomedical electronics since they exhibit optical transmittances above 80% and areal capacitances between 5 and 15 mF cm-2 [53]. The multifunctional transparent supercapacitors constructed on nano-mesh electrodes were also highlighted by Zhao et al. (2021). They achieved capacitance retention of >90% after 1,000 bending cycles while maintaining >75% transmittance, allowing for both optical sensing and energy storage at the same time [15]. Multifunctional stretchable and translucent FSCs that serve as sensors, heaters, or self-powered devices in addition to storing energy are another area of emerging research. Ionic conductivity and optical clarity have been demonstrated by hybrid hydrogel-based transparent supercapacitors, for instance, which maintain capacitances of 20-25 mF cm-2 even after mechanical rupture and repair. For biomedical devices, where small, multipurpose components minimize the overall device footprint, such multifunctional integration is especially alluring.

In conclusion, next generation soft and optical bioelectronics are made possible by stretchable and transparent supercapacitors, which allow for seamless integration with dynamic biological tissues such as skin and eyes. Their ongoing development through self-healing hydrogel systems, nanostructured transparent electrodes, and innovative elastomeric designs places them in a critical position to provide flexible biomedical devices that require both mechanical adaptability and undetectable optical performance.

Hybrid Designs

Hybrid supercapacitors constitute a novel category of devices that reconcile the performance disparity between traditional batteries and electrochemical double-layer capacitors (EDLCs). By amalgamating battery-type faradaic electrodes with capacitor-type materials, these devices merge the elevated energy density of batteries with the rapid charge-discharge rates and extended cycle life of supercapacitors. This equilibrium is especially beneficial in biomedical applications, as devices necessitate enough energy storage for implantable or wearables, with safe, reliable, and prolonged functionality in physiological settings. A prominent illustration of this methodology is the zinc-ion hybrid supercapacitor (ZHS). Recent zinc-ion hybrid supercapacitors (ZHSs) have exhibited exceptionally high energy densities, ranging from 118 to 187 Wh kg?¹, contingent upon electrode architecture, while sustaining power densities of approximately 0.8 to 1 kW kg?¹ [15, 54]. Significantly, when integrated with hydrogel-based electrolytes, these devices demonstrated superior adhesion to soft tissues, mechanical stability during deformation, and biocompatibility, rendering them exceptionally appropriate for implantable biomedical systems.

Alternative hybrid systems have demonstrated significant potential. Fiber-based hybrid supercapacitors, designed with coaxial or twisted configurations, have exhibited volumetric energy densities exceeding 14 mWh cm-3, while retaining over 90% of their capacitance after 1,000 bending cycles, showcasing mechanical durability essential for incorporation into sutures and bio-textiles [55]. Likewise, hybrid MnO?/graphene or Nb?O?/carbon devices have exhibited specific capacitances surpassing 400 F g-1 with consistent cycling over 10,000 cycles, broadening the spectrum of potential electrode combinations that can reconcile performance with stability [56].

Recent research emphasizes the multifunctionality of hybrid BMSCs. Bio-integrated zinc-ion supercapacitors featuring wet-adhesive hydrogel electrolytes offered secure energy storage and exhibited strong adhesion to tissue surfaces, facilitating direct implantation without the need for sutures. These devices exhibited >95% capacity retention after 5,000 cycles under physiological settings and shown no negative inflammatory response in vivo, highlighting their biosafety and long-term functionality [6].

Biocompatibility and In-Vivo Testing

The secure use of flexible supercapacitors in biomedical applications relies not only on their electrochemical efficacy but also on their biocompatibility, which influences the host tissue's response to their presence over time. In contrast to consumer electronics, where devices are physically separated from the user, biomedicine supercapacitors (BMSCs) frequently exist in close proximity to or in direct contact with physiological surroundings. The assessment of their interactions with tissues, cells, and bodily fluids is equally crucial as quantifying capacitance or energy density.

Physiological Assessment Settings

Initial ion-based assessments of flexible supercapacitors (FSCs) are often performed under simulated physiological conditions such as phosphate-buffered saline (PBS), serum, or blood plasma. These testbeds offer vital insights into ionic conductivity, charge retention, electrochemical degradation, and biofouling resistance all crucial for the biocompatibility and operational reliability of FSCs in biomedical or wearable applications. Among promising materials, polymer-coated carbon nanotube (CNT) fiber electrodes have demonstrated steady electrochemical performance when submerged in 0.01 M PBS at 37 °C, a temperature that roughly aligns with human physiology. These CNT electrodes demonstrate resistance to protein adsorption and surface fouling, which are common breakdown mechanisms in vivo. These findings indicate that surface engineering, such as polymer coatings, can markedly improve device stability in ion-rich biological environments [57]. Moreover, 3D porous grapheme-MXene composite electrodes have exhibited prolonged operating stability in albumin-enriched PBS, simulating protein-rich biological fluids such as serum. Their architecture not only offers a high electroactive surface area but also inhibits non-specific protein binding, hence enhancing their antifouling properties and appropriateness for bio-interfaced electronics [58]. Hybrid graphene/CNT-based electrodes have been investigated in enzymatic biofuel cell platforms, where they were subjected to both PBS and serum environments. These devices highlight dual functionality acting as both energy storage and bio electrochemical conversion units. Notwithstanding the existence of intricate organic and ionic compounds in serum, these electrodes exhibited steady performance, underscoring their potential for implantable or skin-interfaced power systems [59].

These findings together indicate that material architecture, surface functionalization, and electrolyte compatibility are essential for the reliable operation of FSCs in physiological environments. These qualities are essential for nascent applications in biosensing, implantable electronics, and self-sustaining health monitoring systems.

Cytocompatibility and Hemocompatibility

Biocompatibility is fundamental in assessing flexible supercapacitors (FSCs) for biomedical applications. This entails evaluating cytotoxicity, cell proliferation, and adhesion, generally employing fibroblast or myoblast cell lines. Conductive polymers, including poly(3,4-ethylenedioxythiophene): poly (styrene sulfonate) (PEDOT: PSS), polyaniline (PANI), and polypyrrole (PPy), have consistently exhibited strong cytocompatibility, facilitating fibroblast and myoblast growth without eliciting deleterious effects. These materials exhibit superior electrochemical performance, with specific capacitances reported between 200 and 600 F·g?¹, contingent upon the synthesis technique and electrolyte conditions [60].

Hydrogel-based flexible supercapacitors are being rigorously investigated for implantable and wearable applications owing to their mechanical durability and biocompatibility. Jeon et al. (2025) revealed that thermally drawn hydrogel supercapacitor fibers maintained approximately 96% capacitance after 1,000 bending cycles, concurrently verifying elevated 3T3 fibroblast survival in cytotoxicity assessments [61]. Liu et al. (2025) similarly showed the fibroblast compatibility of gelatin- and metal-coordinated hydrogel FSCs, confirming their safety for prolonged bio interfaces [62]. In addition to cytocompatibility, hemocompatibility is essential for devices designed for intravascular or blood-contacting applications. ISO 10993-4 mandates testing for hemolysis, thrombogenicity, and coagulation time to confirm that electrode surfaces do not induce red blood cell lysis or thrombus formation. Materials like PEDOT: PSS and hydrogel-CNT composites exhibit favorable hemocompatibility profiles, with hemolysis rates below 2%, according to ISO standards. Furthermore, several graphene-based and hydrogel-coated electrodes demonstrate non-thrombogenic surfaces owing to their smooth topographies and hydrated coatings that inhibit protein adhesion and platelet activation.

Encapsulation and Toxicity Reduction

While carbon- and polymer-based electrodes (e.g., CNTs, PEDOT: PSS, PPy) are typically cytocompatibility, metal oxides and nitrides (e.g., TiN, NbN, ZnO, and MoO?) present significant hurdles in biomedical applications due to ion leaching in physiological fluids. Ions that are released can cause cytotoxicity, inflammatory reactions, or local tissue irritation, which limits their direct application in implantable supercapacitors. To address these restrictions, encapsulation strategies have been frequently used to provide diffusion barriers while retaining electrochemical performance. Parylene C encapsulation, achieved through chemical vapor deposition, provides a conformal, pinhole-free protective layer that resists metal ion migration. Liu et al. used parylene encapsulation in implantable supercapacitors, demonstrating improved stability in PBS and effective protection of underlying metal components, hence decreasing cytotoxic hazards [63]. Similarly, silk fibroin coatings have been identified as biodegradable and biocompatible encapsulants. Lima et al. showed that silk fibroin encapsulation stabilized energy storage devices immersed in PBS, highlighting biodegradability and tissue safety while maintaining electrochemical activity [64]. In a broader review, silk proteins' have ability to form biocompatible, antifouling layers for bioelectronics, reducing protein adsorption and inflammation responses when interfaced with tissue [65].

Surface engineering techniques to TiN electrodes have also been proposed. Also, it was found that tailoring TiN surface roughness improved the fibrous encapsulation response in vivo, reducing chronic tissue irritation while maintaining desirable conductivity for neural interfacing electrodes [66]. These findings indicate that encapsulation techniques can be paired with surface modification to further limit undesirable host reactions. Another interesting approach is encapsulation with hydrogels, which provide hydrated, ion-permeable matrices that allow ionic conduction but prevent ion leaching. Kim et al. identified hydrogel-based encapsulation as a versatile barrier layer for bio supercapacitors, allowing for long-term electrochemical stability in PBS while minimizing tissue exposure to potentially harmful degradation products [67].

In Vivo Testing

Flexible supercapacitor (FSC) research has moved from in vitro cytocompatibility assays to in vivo implantation studies due to recent advancements in bioelectronics, indicating the devices' translational potential. Important information about inflammatory responses, biodegradation, and long-term electrochemical stability in live tissue settings is provided by in vivo validation. At the forefront of this effort are gadgets based on hydrogel. The suitability of the hydrogels for bioelectronic applications was established by Fu et al. (2020) after they implanted conductive hydrogel electrodes in rat subcutaneous tissue [68]. Histological analysis verified minimal inflammatory infiltration and sustained tissue integration over a period of several weeks. In a similar vein, Kim et al. (2024) examined hydrogel nanocomposite supercapacitors and emphasized research on animals in which hydrogel-based microdevices implanted in rat cardiac and subcutaneous sites preserved structural and electrochemical stability while only causing brief inflammatory reactions that went away without fibrosis [69].

Another interesting substrate and encapsulating material for in vivo FSCs is silk fibroin. In BALB/c mice, Li et al. (2018) reported the subcutaneous implantation of silk fibroin-based biodegradable electronic devices. Histological analysis revealed no chronic inflammation or fibrotic encapsulation and the silk substrate's safe, gradual resorption [70]. Histology verified the absence of fibrotic encapsulation or necrosis, and Lv et al. (2025) reviewed silk-based bioelectronic implants, describing silk fibroin-coated micro supercapacitors embedded in rat muscle tissue that maintained electrochemical stability during repeated charge-discharge cycling [71]. These results highlight the importance of biodegradable encapsulating strategies, like silk fibroin and hydrogels, in lowering host immune responses while maintaining device functionality in vivo. Together, the findings show that FSCs may be designed for long-term stability, safety, and integration with live tissues, opening the door to medical applications using implantable energy storage devices.

Standards and Clinical Translation

The transition from lab-scale devices to clinical implementation of flexible supercapacitors (FSCs) necessitates adherence to globally accepted safety standards. In order to ensure repeatability and comparability among laboratories, the ISO 10993 series, in particular ISO 10993-1 and ISO 10993-4, establishes standards for cytotoxicity, hemocompatibility, irritation, sensitization, and systemic toxicity testing. To align regulatory approval with biocompatibility outcomes, the U.S. Food and Drug Administration (FDA) also offer guidance documents on biological evaluation of medical devices [72, 73]. There are still major obstacles in the way of converting preclinical FSC research into clinical practice, even with these well-established frameworks. The long-term breakdown of materials is a significant problem because it may leak nanoparticles or metal ions into the surrounding tissue or circulation, with unclear systemic implications. The creation of bioresorbable electronic systems and encapsulation techniques are crucial for reducing these dangers, according to recent reviews [74, 75].

Scalability and sterilization present another difficulty. Optimized sterilization-compatible designs are necessary because polymeric or hydrogel-based FSCs can be degraded by traditional sterilization techniques like autoclaving or gamma irradiation. Additionally, encapsulating materials like silk fibroin, hydrogels, or parylene C need to be designed to maintain their barrier qualities while withstanding sterilization [2].

Future translation will probably focus on designing fully biodegradable supercapacitors, in which the encapsulants and active components safely break down into non-toxic byproducts after their useful lives. For instance, transient energy storage units in animal models have been successfully investigated using biodegradable silk fibroin, magnesium, and polymer composites [7]. There are also plans for multifunctional bio interfaces, in which FSCs serve as biosensors, stimulators, or drug-delivery platforms in addition to storing energy, allowing for integrated theragnostic applications [76].

Biomedical Applications of Flexible Supercapacitors

Implantable Devices

Because of their quick charge and discharge, long cycling stability, and increased safety over traditional batteries which are vulnerable to leakage and thermal runaway flexible supercapacitors (FSCs) are being investigated more and more as power sources for implantable biomedical devices like pacemakers, cochlear implants, neural stimulators, and biosensors [77]. Recent developments show how useful they can be. Wang et al. (2024) described an anticoagulant FSC based on heparin-doped PEDOT (PEDOT: Hep) that successfully powered an implanted heart-rate sensor in mice while achieving a hemolysis rate below 5%, a coagulation time of approximately 63.4 s, and excellent cycling stability with approximately 76.24% capacitance retention after 20,000 cycles [78]. A fully biodegradable implantable FSC with an energy density of approximately 15.64 μWh cm?² and an aerial capacitance of 112.5 mF cm?² at 1 mA cm?² was also developed by Sheng et al. (2021). It is intended to safely decompose in vivo following its functional lifespan [31]. The precise values of 50-70 mF cm?² and >90% retention after 5,000 cycles need source confirmation, but FSCs made with carbon nanostructures and conducting polymer composites like CNT-PEDOT have demonstrated areal capacitances in the tens of mF cm?² range and high cycling retention in artificial cerebrospinal fluid, indicating suitability for powering brain–machine interfaces in the context of neural implants. More generally, reviews point out that because of their electrical conductivity, mechanical flexibility, and biocompatibility, materials like graphene, carbon nanotubes, MXenes, and transition-metal oxides are excellent choices for implantable FSCs [31].

Wearable

Power supplies for wearable medical devices like continuous monitoring patches and smart wound dressings must be biocompatible, lightweight, and conformal. In order to facilitate wireless health monitoring without the bulk or safety hazards associated with batteries, flexible supercapacitors (FSCs) can be included straight into bandages or skin-contact patches due to their ability to be built into soft substrates. For instance, in a recent study, Luo et al. (2025) created a hydrogel-based FSC embedded in a smart wound dressing that could track temperature and pH variations at the wound interface. According to the manuscript, the device demonstrated an aerial capacitance of about 25 mF cm?² and continued to function steadily for a week in humid conditions.

The trajectory and capabilities of such systems are demonstrated by supporting literature, even though instances with precise figures are still being developed. There is evidence that smart bandages can sense pH in real time. Mariani et al. (2021) developed a flexible bandage sensor that can continually check the pH of a wound, correlate it to the healing stages, and maintain its functionality in moist wound circumstances [72]. Wearable dressings with temperature and pH sensors are also being investigated as potential platforms for closed-loop wound care. Sustainable pH monitoring dressings were recently described by Zhu et al. (2025), who emphasized the importance of long-term stability under physiologically relevant settings [79].

In addition to sensing, attempts are being made to integrate stimulus delivery and energy storage into a single device. In order to offer both power and therapeutic electrical stimuli to speed healing, a recent study, for example, suggests integrating supercapacitors with sodium hyaluronate hydrogel to generate a "self-powered electronic stimulation wound dressing [80]. A significant benefit in wearable clinical or residential settings is the potential for the FSC to sense and deliver localized currents in such multifunctional designs, doing away with the need for external power or separate batteries.

Bioelectronic Skins

For bioelectronic skins (e-skins), where sensing, actuation, and communication must be co-integrated on a soft, skin-conformal substrate, transparent and flexible FSCs are essential building pieces. A transparent flexible supercapacitor (FTSC) and a stretchable strain sensor were combined to create a self-powered, all-in-one transparent e-skin [81]. By using oxygen-deficient MoO? nanowires and cellulose nanofiber composites as electrodes, the FTSC was able to power the sensor module with an aerial capacitance of approximately 12.1 mF cm?² and a transparency of over 75%. The e-skin allowed for the real-time monitoring of minute physiological strains while maintaining functionality during deformation. At the same time, work on stretchable supercapacitors that combine graphene and MXene materials has progressed. For example, flexible MXene-graphene composites have been investigated as highly transparent and mechanically durable conductive films. In these hybrid systems, optical transmittance can exceed 70-80% while maintaining acceptable electrical performance, which is essential for energy modules that are skin-mounted and unseen [82, 83].

Fully stretchy devices have been demonstrated in addition to composites. A transparent, stretchy graphene supercapacitor based on wrinkled graphene that could withstand mechanical strains without losing its transparency was described by Chen et al. (2014) [84]. Although it had a lower areal capacitance (~a few mF cm?²) and capacity retention over repeated deformation cycles, a transparent, stretchable solid-state supercapacitor made of a serpentine-structured MnO?-Au-Ni mesh electrode demonstrated both optical transparency and mechanical resilience more recently [85].

Drug Delivery Platforms

Electro-responsive medication delivery systems can be powered by localized, precisely controlled energy pulses made possible by micro-supercapacitors (MSCs). These approaches do away with the requirement for large external power modules by using short voltage bursts to trigger release from conductive polymers or ionically actuatable hydrogels. In order to achieve on-demand pulsatile administration, Yi et al. (2015), for instance, showed how to utilize square voltage pulses across electrodes to release ionic medicines trapped in a hydrogel [86]. In similar systems, drug reservoirs contain electro-active polymers that react to applied potentials to govern drug movement or volumetric expansion/contraction for regulated release [87]. Furthermore, it has been demonstrated that soft implantable platforms that combine drug reservoirs with supercapacitors may control drug flow by varying the electrical supply [88]. These instances show how FSC/MSC technology may develop into small, battery-free, self-sustaining medication delivery patches.

Challenges and Future Perspectives

Although flexible biocompatible supercapacitors (BMSCs) have made remarkable strides, there are still many obstacles to overcome before they may be used in clinical or commercial settings. Energy density versus biocompatibility is one basic trade-off. Although transition metal oxides are frequently employed due to their high pseudo capacitance, potential ion leaching and toxicity make their application in biological contexts challenging. For instance, flexible NbN-TiN supercapacitors based on physiological fluids have been found to exhibit steady performance under biofluidic settings [24]. However, rather than focusing on long-term in vivo biocompatibility, these studies typically highlight device performance under in vitro or simulated physiological circumstances.

Carbon-based materials, on the other hand, typically show superior biological compatibility. Hydrophilic carbon nanotube fiber supercapacitors are a noteworthy example; they still maintained around 98.3% of their capacitance after 10,000 cycles and continued to function even after being bent and exposed to conditions containing serum or blood [8]. This demonstrates that, although generally having lower energy densities than some oxide-based systems, carbon nanostructures can provide great stability in physiologically relevant fluids.

Mechanically, fully biocompatible fiber supercapacitors made by thermal drawing demonstrated exceptional mechanical and electrochemical resilience: they maintained approximately 96.5% of their initial capacitance after 1,000 bending cycles, and the encapsulated devices maintained 92-98.8% of their performance after 20 weeks in phosphate-buffered saline (PBS) immersion [61]. One of the few studies demonstrating sustained immersion stability in physiological settings is this one. Recent developments in biocompatible miniature/micro-supercapacitors hold promise in the field of miniaturization. Although Luo et al. (2025) concentrate more on the architecture and flexibility than in vivo deployment, they report MSCs with around 94% capacitance retention after 3,000 bending cycles and 93% retention over 3,000 charge-discharge cycles [6]. These findings demonstrate that MSCs can retain mechanical and electrochemical stability at reduced scales; nonetheless, there are still issues with integrating into biological systems and guaranteeing adequate capacity per footprint.

Recently a review titled “Revolutionizing Implantable Technology: Biocompatible Supercapacitors as the Future of Power Sources” examines a large number of other BMSC-related research and talks about the current disconnect between reliable, secure devices for long-term biomedical use and high-performance lab prototypes [7].

Journal of Biomedical Science and Research