Tough gelatin-based biogels for wearable sensors

Abstract

Flexible wearable sensors that can intimately adhere to the human body for real-time monitoring of human activities and physiological signals have attracted great attention owing to their potential in personalized healthcare and human-machine interfaces. Gelatin-based biogels are promising materials in wearable sensors due to their good biocompatibility, biodegradability, and sustainability. However, conventional gelatin-based biogels are usually weak and brittle (tensile strength < 10 kPa and stretchability < 50%), and thus cannot be applied in flexible wearable devices. Therefore, further efforts are needed to engineer tough gelatin-based biogels that meet the demands of flexible wearable sensors. In this perspective, we summarize recent progress in designing tough gelatin-based biogels and their wide applications in wearable sensing devices, while highlighting potential future directions in this field.

Keywords

Gelatin / biogel / stretchability / mechanical toughness / wearable sensor

References

[1] Ates HC,Gonzalez-Macia L.End-to-end design of wearable sensors.Nat Rev Mater2022;7:887-907 PMCID:PMC9306444

[2] Chen C,Wang J.Digital health for aging populations.Nat Med2023;29:1623-30.

[3] Gong S,Yin J,Cheng W.Materials-driven soft wearable bioelectronics for connected healthcare.Chem Rev2024;124:455-553

[4] Han F,Liu G.Materials with tunable optical properties for wearable epidermal sensing in health monitoring.Adv Mater2022;34:e2109055

[5] Wang L,Zhang X.Multifunctional conductive hydrogel-based flexible wearable sensors.TrAC Trends Anal Chem2021;134:116130

[6] Sun G,Jiang Y,Meng C.Recent advances in flexible and soft gel-based pressure sensors.Soft Sci2022;2:17

[7] Gao D,Lee PS.Natural polymer in soft electronics: opportunities, challenges, and future prospects.Adv Mater2022;34:e2105020

[8] Wang C,Someya T.Natural biopolymer-based biocompatible conductors for stretchable bioelectronics.Chem Rev2021;121:2109-46

[9] Wang Z,Huang Y,Chen J.Naturally sourced hydrogels: emerging fundamental materials for next-generation healthcare sensing.Chem Soc Rev2023;52:2992-3034

[10] Wang C.Functionalization of natural-derived biogels for soft bioelectronics.Acc Mater Res2024;5:1-5

[11] Zeng Q,Shi G.Biogel library-accelerated discovery of all-natural bioelectronics.ACS Sens2024;9:6685-97

[12] Campiglio CE,Farè S.Cross-linking strategies for electrospun gelatin scaffolds.Materials (Basel)2019;12:2476 PMCID:PMC6695673

[13] Zhou L,Fan L.Injectable Self-healing natural biopolymer-based hydrogel adhesive with thermoresponsive reversible adhesion for minimally invasive surgery.Adv Funct Mater2021;31:2007457

[14] Balakrishnan G,Naik D.Gelatin-based ingestible impedance sensor to evaluate gastrointestinal epithelial barriers.Adv Mater2023;35:e2211581 PMCID:PMC10192083

[15] Mao L,Fu Y.Transglutaminase modified type A gelatin gel: The influence of intra-molecular and inter-molecular cross-linking on structure-properties.Food Chem2022;395:133578

[16] Zhao X.Multi-scale multi-mechanism design of tough hydrogels: building dissipation into stretchy networks.Soft Matter2014;10:672-87 PMCID:PMC4040255

[17] Xu C,Zhao S.Mechanical regulation of polymer gels.Chem Rev2024;124:10435-508

[18] Zhang CW,Chen C.Hierarchical engineering for biopolymer-based hydrogels with tailored property and functionality.Adv Mater2025;37:e2414897

[19] He Q,Wang S.Hofmeister effect-assisted one step fabrication of ductile and strong gelatin hydrogels.Adv Funct Mater2018;28:1705069

[20] Yuan X,Xia P.Tough gelatin hydrogel for tissue engineering.Adv Sci (Weinh)2023;10:e2301665 PMCID:PMC10460895

[21] Wei Y,Wang C,Zhao B.Asymmetric “Janus” biogel for human-machine interfaces.Adv Funct Mater2023;33:2214366

[22] Qin Z,Yao M.Freezing-tolerant supramolecular organohydrogel with high toughness, thermoplasticity, and healable and adhesive properties.ACS Appl Mater Interfaces2019;11:21184-93

[23] Xu L,Cui Y,Qiao Y.Conjoined-network rendered stiff and tough hydrogels from biogenic molecules.Sci Adv2019;5:eaau3442 PMCID:PMC6358320

[24] Yang S,Wang T,Tong Z.Ultrafast and programmable shape memory hydrogel of gelatin soaked in tannic acid solution.ACS Appl Mater Interfaces2020;12:46701-9

[25] Gu Y,Wang Y.Compressible, anti-fatigue, extreme environment adaptable, and biocompatible supramolecular organohydrogel enabled by lignosulfonate triggered noncovalent network.Nat Commun2025;16:160 PMCID:PMC11696470

[26] Huang Y,Ren C.High-strength gelatin hydrogel scaffold with drug loading remodels the inflammatory microenvironment to enhance osteoporotic bone repair.Adv Mater2025;37:e2501051

[27] Ren C,Liao Y.Reinforcing gelatin hydrogels via in situ phase separation and enhanced interphase bonding for advanced 3D fabrication.Adv Mater2025;37:e2416432

[28] Baumgartner M,Drack M.Resilient yet entirely degradable gelatin-based biogels for soft robots and electronics.Nat Mater2020;19:1102-9

[29] Song H,Gan T.Gelatin biogel-liquid metal composite transient circuits for recyclable flexible electronics.Adv Mater Technol2024;9:2301483

[30] Hao XP,Zhang XN.Healable, recyclable, and multifunctional soft electronics based on biopolymer hydrogel and patterned liquid metal.Small2022;18:e2201643

[31] Jia L,Ren A,Zhou S.Degradable and recyclable hydrogels for sustainable bioelectronics.ACS Appl Mater Interfaces2024;16:32887-905

[32] Song X,Liu Z.Natural protein-based biogels with biomimetic mechanics and multifunctionality for skin sensors.ACS Mater Lett2025;7:202-9

[33] Wei S,Zhao W,Zhao W.Mechanically robust gelatin gel for sensitive touch sensor based on electrode potential.Adv Funct Mater2024;34:2408648

[34] Tordi P,Jeong Y,Samorì P.Multiresponsive ionic conductive alginate/gelatin organohydrogels with tunable functions.Adv Funct Mater2024;34:2410663

[35] Lu X,Liu Z.Robust, efficient, and recoverable thermocells with zwitterion-boosted hydrogel electrolytes for energy-autonomous and wearable sensing.Angew Chem Int Ed Engl2024;63:e202405357

[36] Wang C,Wang B.On-skin paintable biogel for long-term high-fidelity electroencephalogram recording.Sci Adv2022;8:eabo1396 PMCID:PMC9122322

[37] Li L,Ji Z.Paintable, fast gelation, highly adhesive hydrogels for high-fidelity electrophysiological monitoring wirelessly.Small2025;21:e2407996

[38] Lan L,Li H.Skin-inspired all-natural biogel for bioadhesive interface.Adv Mater2024;36:e2401151

[39] Shin SR,Zalabany M.Carbon-nanotube-embedded hydrogel sheets for engineering cardiac constructs and bioactuators.ACS Nano2013;7:2369-80

[40] Yin R,Shao J.Integration of flexible, recyclable, and transient gelatin hydrogels toward multifunctional electronics.J Mater Sci Technol2023;145:83-92

[41] Wan C,Ren M.In situ formation of conductive epidermal electrodes using a fully integrated flexible system and injectable photocurable ink.ACS Nano2023;17:10689-700

[42] Zhang YZ,Jiang Q.MXene hydrogels: fundamentals and applications.Chem Soc Rev2020;49:7229-51

[43] Wang X,Yin J.Mechanically robust, degradable and conductive MXene-composited gelatin organohydrogel with environmental stability and self-adhesiveness for multifunctional sensor.Compos Part B Eng2022;241:110052

[44] Picchio ML,Casado N.Mixed ionic and electronic conducting eutectogels for 3d‐printable wearable sensors and bioelectrodes.Adv Mater Technol2022;7:2101680

[45] Li T,Zhao C.Robust skin-integrated conductive biogel for high-fidelity detection under mechanical stress.Nat Commun2025;16:88 PMCID:PMC11695986