Recent advances of sweat sampling, sensing, energy-harvesting and data-display toward flexible sweat electronics

Abstract

Sweat contains diverse types of biomarkers that can mirror an individual’s health condition. The forefront research of sweat monitoring primarily focuses on sensing basic parameters, i.e., sweat rate and single electrolyte imbalances in controlled laboratory settings. However, recent works show the potential of sweat for the rich biomarkers in aspects of comprehensive health status display, timely safety alarming, and energy harvesting. The advances in wearable flexible electronics enable continuous, real-time, noninvasive detection of multiple sweat components, providing molecular-level insights into human physiology and psychology information; additionally, the efficient sweat extraction technologies of flexible electronics promote its application in energy harvesting, contributing to advancing a flexible sweat platform. This review comprehensively explores flexible sweat-based electronics, encompassing four key aspects: sweat sampling methods, sweat-based sensors, sweat-based energy harvesters, and sweat data display methods. Firstly, the traditional sweat-based platform is discussed in sweat sampling, sensing, and data analysis. Then, the development of wearable sweat sampling methods is discussed with a comparison of the traditional sweat collection methods. After that, the recent advances in sweat-based biosensors for monitoring diverse sweat analytes, such as the perspiration volume, glucose, lactate, and uric acid levels, are summarized. Subsequently, this review also highlights the recent progress and potential value of sweat-based energy harvesters in sweat-activated batteries and bio-fuel cells. Furthermore, multiple data display methods are proposed to achieve accurate feedback on health status, such as colorimetric techniques, light-emitting diodes, actuators, etc. Finally, this review concludes the main current challenges faced in practical applications of sweat-based bioelectronic systems and proposes a vision for the future evolution of this promising field.

Keywords

Sweat electronics / sweat sampling / sweat sensing / sweat-based energy harvester / data display

References

[1] Kaya T,Ho J.Wearable sweat sensors: background and current trends.Electroanalysis2019;31:411-21

[2] Ye C,Min J.A wearable aptamer nanobiosensor for non-invasive female hormone monitoring.Nat Nanotechnol2024;19:330-7 PMCID:PMC10954395

[3] Song Y,Li J.3D-printed epifluidic electronic skin for machine learning - powered multimodal health surveillance.Sci Adv2023;9:eadi6492 PMCID:PMC10499321

[4] Mukasa D,Min J.A computationally assisted approach for designing wearable biosensors toward non-invasive personalized molecular analysis.Adv Mater2023;35:2212161

[5] Torrente-Rodríguez RM,Yang Y.Investigation of cortisol dynamics in human sweat using a graphene-based wireless mHealth system.Matter2020;2:921-37 PMCID:PMC7138219

[6] Yang Y,Bo X.A laser-engraved wearable sensor for sensitive detection of uric acid and tyrosine in sweat.Nat Biotechnol2020;38:217-24

[7] Lorestani F,Abdullah AM.A highly sensitive and long-term stable wearable patch for continuous analysis of biomarkers in sweat.Adv Funct Mater2023;33:2306117 PMCID:PMC10959519

[8] Liu S,Wang S.Soft, environmentally degradable microfluidic devices for measurement of sweat rate and total sweat loss and for colorimetric analysis of sweat biomarkers.EcoMat2023;5:e12270

[9] Tu J,Song Y.A wireless patch for the monitoring of C-reactive protein in sweat.Nat Biomed Eng2023;7:1293-306 PMCID:PMC10592261

[10] Gao F,Zhang L.Wearable and flexible electrochemical sensors for sweat analysis: a review.Microsyst Nanoeng2023;9:1 PMCID:PMC9805458

[11] Ji W,Wu W.Wearable sweat biosensors refresh personalized health/medical diagnostics.Research2021;2021:9757126 PMCID:PMC8557357

[12] Choi J,Baker LB.Skin-interfaced systems for sweat collection and analytics.Sci Adv2018;4:eaar3921 PMCID:PMC5817925

[13] Sempionatto JR,Mahato K,Gao W.Wearable chemical sensors for biomarker discovery in the omics era.Nat Rev Chem2022;6:899-915 PMCID:PMC9666953

[14] Xu L,Fan M.Advances in wearable flexible electrochemical sensors for sweat monitoring: a mini-review.Int J Electrochem Sci2023;18:13-9

[15] Tabasum H,Mishra R.Wearable microfluidic-based e-skin sweat sensors.RSC Adv2022;12:8691-707 PMCID:PMC8985157

[16] Nyein HYY,Tran B.A wearable patch for continuous analysis of thermoregulatory sweat at rest.Nat Commun2021;12:1823 PMCID:PMC7987967

[17] Tai LC,Lin Y.Wearable sweat band for noninvasive levodopa monitoring.Nano Lett2019;19:6346-51

[18] Tai LC,Chao M.Methylxanthine drug monitoring with wearable sweat sensors.Adv Mater2018;30:1707442

[19] Friedel M,Kasting G.Opportunities and challenges in the diagnostic utility of dermal interstitial fluid.Nat Biomed Eng2023;7:1541-55

[20] Jadoon S,Akram MR.Recent developments in sweat analysis and its applications.Int J Anal Chem2015;2015:164974 PMCID:PMC4369929

[21] Teymourian H,Wang J.Electrochemical glucose sensors in diabetes management: an updated review (2010-2020).Chem Soc Rev2020;49:7671-709

[22] Villiger M,Vetsch T.Evaluation and review of body fluids saliva, sweat and tear compared to biochemical hydration assessment markers within blood and urine.Eur J Clin Nutr2018;72:69-76 PMCID:PMC5765170

[23] Heikenfeld J,Feldman B.Accessing analytes in biofluids for peripheral biochemical monitoring.Nat Biotechnol2019;37:407-19

[24] Aslan R,Bostancı Hİ,Akgür SA.Development of analytical method for illegal substances in sweat and comparison of the effectiveness of sweat collection materials.Leg Med2023;64:102264

[25] Nyein HY,Shahpar Z.A wearable electrochemical platform for noninvasive simultaneous monitoring of Ca²⁺ and pH.ACS Nano2016;10:7216-24

[26] Bariya M,Javey A.Wearable sweat sensors.Nat Electron2018;1:160-71

[27] Min J,Xu C.Skin-interfaced wearable sweat sensors for precision medicine.Chem Rev2023;123:5049-138 PMCID:PMC10406569

[28] Ghaffari R,Ray TR.Recent progress, challenges, and opportunities for wearable biochemical sensors for sweat analysis.Sens Actuators B Chem2021;332:129447 PMCID:PMC7853653

[29] Zhou J,Zhang X.Progress in wearable sweat sensors and their applications.Chinese J Anal Chem2022;50:87-96

[30] Zhang S,Xu X,Hu J.Fibers/textiles-based flexible sweat sensors: a review.ACS Mater Lett2023;5:1420-40

[31] Luo Y,Ahn JH.Technology roadmap for flexible sensors.ACS Nano2023;17:5211-95

[32] Shen H,Ma Y,Chen L.Recent advances toward wearable sweat monitoring systems.Adv Mater Technol2023;8:2200513

[33] Manjakkal L,Dahiya R.Correction: Flexible potentiometric pH sensors for wearable systems.RSC Adv2020;10:12734 PMCID:PMC9051454

[34] Kim J,Yang DS.A skin-interfaced, miniaturized platform for triggered induction, capture and colorimetric multicomponent analysis of microliter volumes of sweat.Biosens Bioelectron2024;253:116166

[35] Manjakkal L,Nathan A,Dahiya R.Energy autonomous sweat-based wearable systems.Adv Mater2021;33:2100899

[36] Yin L,Liu R.Wearable e-skin microgrid with battery-based, self-regulated bioenergy module for epidermal sweat sensing.Adv Energy Mater2023;13:2203418

[37] Xiao G,Li M.Weavable yarn-shaped supercapacitor in sweat-activated self-charging power textile for wireless sweat biosensing.Biosens Bioelectron2023;235:115389

[38] Moonen EJ,Peri E,Mischi M.Wearable sweat sensing for prolonged, semicontinuous, and nonobtrusive health monitoring.VIEW2020;1:20200077

[39] Xing Z,Lin B,Mao H.Recent advances in wearable sensors for the monitoring of sweat: a comprehensive tendency summary.Chemosensors2023;11:470

[40] Clark KM.Recent advances in skin-interfaced wearable sweat sensors: opportunities for equitable personalized medicine and global health diagnostics.ACS Sens2023;8:3606-22

[41] Qiao Y,Chen Z,Gao L.Wearable sensor for continuous sweat biomarker monitoring.Chemosensors2022;10:273

[42] Mohan A,Mishra RK.Recent advances and perspectives in sweat based wearable electrochemical sensors.TrAC Trends Anal Chem2020;131:116024

[43] Liu C,Wang D.The role of sampling in wearable sweat sensors.Talanta2020;212:120801

[44] Shirreffs SM.Whole body sweat collection in humans: an improved method with preliminary data on electrolyte content.J Appl Physiol1997;82:336-41

[45] Ono E,Mori Y.Sweat glucose and GLUT2 expression in atopic dermatitis: implication for clinical manifestation and treatment.PLoS One2018;13:e0195960 PMCID:PMC5909908

[46] Baker LB,Barnes KA,Reimel AJ.Validity and reliability of a field technique for sweat Na⁺ and K⁺ analysis during exercise in a hot-humid environment.Physiol Rep2014;2:e12007 PMCID:PMC4098735

[47] Baker LB,Barnes KA.Skin-interfaced microfluidic system with personalized sweating rate and sweat chloride analytics for sports science applications.Sci Adv2020;6:eabe3929 PMCID:PMC7732194

[48] Brueck A,Stannard AB,Kaya T.A real-time wireless sweat rate measurement system for physical activity monitoring.Sensors2018;18:533 PMCID:PMC5855985

[49] Huang X,Chen K.Stretchable, wireless sensors and functional substrates for epidermal characterization of sweat.Small2014;10:3083-90

[50] Dai B,Shi L.Bioinspired Janus textile with conical micropores for human body moisture and thermal management.Adv Mater2019;31:1904113

[51] Zhong B,Wang L.Wearable sweat loss measuring devices: from the role of sweat loss to advanced mechanisms and designs.Adv Sci2022;9:e2103257 PMCID:PMC8728835

[52] Jain V,Jiang H,Ziaie B.A mass-customizable dermal patch with discrete colorimetric indicators for personalized sweat rate quantification.Microsyst Nanoeng2019;5:29 PMCID:PMC6572848

[53] Kabiri K.Porous superabsorbent hydrogel composites: synthesis, morphology and swelling rate.Macro Mater Eng2004;289:653-61

[54] Sempionatto JR,Wang J.Touch-based fingertip blood-free reliable glucose monitoring: personalized data processing for predicting blood glucose concentrations.ACS Sens2021;6:1875-83

[55] Wang S,Gu Y.Wearable sweatband sensor platform based on gold nanodendrite array as efficient solid contact of ion-selective electrode.Anal Chem2017;89:10224-31

[56] Wu CH,Baessler P,Ray TR.Skin-interfaced microfluidic systems with spatially engineered 3D fluidics for sweat capture and analysis.Sci Adv2023;9:eadg4272 PMCID:PMC10881187

[57] Zhang Y,Huang J.Skin-interfaced microfluidic devices with one-opening chambers and hydrophobic valves for sweat collection and analysis.Lab Chip2020;20:2635-45

[58] Son J,Lee S.Cactus-spine-inspired sweat-collecting patch for fast and continuous monitoring of sweat.Adv Mater2021;33:2102740

[59] Song Y,Yu Y.Wireless battery-free wearable sweat sensor powered by human motion.Sci Adv2020;6:eaay9842 PMCID:PMC7527225

[60] Bandodkar AJ,Choi J.Battery-free, skin-interfaced microfluidic/electronic systems for simultaneous electrochemical, colorimetric, and volumetric analysis of sweat.Sci Adv2019;5:eaav3294 PMCID:PMC6357758

[61] Emaminejad S,Wu E.Autonomous sweat extraction and analysis applied to cystic fibrosis and glucose monitoring using a fully integrated wearable platform.Proc Natl Acad Sci U S A2017;114:4625-30 PMCID:PMC5422810

[62] Kim J,Imani S.Noninvasive alcohol monitoring using a wearable tattoo-based iontophoretic-biosensing system.ACS Sens2016;1:1011-9

[63] Xu G,Shi R.Triboelectric nanogenerator enabled sweat extraction and power activation for sweat monitoring.Adv Funct Mater2024;34:2310777

[64] Hammond KB,Gibson LE.Clinical evaluation of the macroduct sweat collection system and conductivity analyzer in the diagnosis of cystic fibrosis.J Pediatr1994;124:255-60

[65] Yeung KK,Hua Y,Yuen MMF.Recent advances in electrochemical sensors for wearable sweat monitoring: a review.IEEE Sensors J2021;21:14522-39

[66] Yin J,Reddy VS,Ramakrishna S.Flexible textile-based sweat sensors for wearable applications.Biosensors2023;13:127 PMCID:PMC9856321

[67] Naik AR,Dey AA.Printed microfluidic sweat sensing platform for cortisol and glucose detection.Lab Chip2022;22:156-69

[68] Patterson MJ,Nimmo MA.Variations in regional sweat composition in normal human males.Exp Physiol2000;85:869-75

[69] Huang X,Zhou J.Garment embedded sweat-activated batteries in wearable electronics for continuous sweat monitoring.npj Flex Electron2022;6:10

[70] Baker LB,Anderson ML,Stofan JR.Normative data for regional sweat sodium concentration and whole-body sweating rate in athletes.J Sports Sci2016;34:358-68

[71] Krabak BJ,Waite BL.Exercise-associated hyponatremia, hypernatremia, and hydration status in multistage ultramarathons.Wilderness Environ Med2017;28:291-8

[72] Kim T,Hoang E.A 3D printed wearable bioelectronic patch for multi-sensing and in situ sweat electrolyte monitoring.Adv Mater Technol2021;6:2001021

[73] Takahashi A,Sasaki K.Relationships of hyperchloremia with hypertension and proteinuria in patients with chronic kidney disease.Clin Exp Nephrol2022;26:880-5

[74] Montes-García V,Wang Y.Harnessing selectivity and sensitivity in ion sensing via supramolecular recognition: a 3D hybrid gold nanoparticle network chemiresistor.Adv Funct Mater2021;31:2008554

[75] Guinovart T,Windmiller JR,Wang J.A potentiometric tattoo sensor for monitoring ammonium in sweat.Analyst2013;138:7031-8

[76] Hu Y,Li J.Thin, soft, skin-integrated electronics for real-time and wireless detection of uric acid in sweat.Int J Smart Nano Mater2023;14:406-19

[77] Gao W,Shahpar Z.Wearable microsensor array for multiplexed heavy metal monitoring of body fluids.ACS Sens2016;1:866-74

[78] Kim J,Samek IA.Wearable temporary tattoo sensor for real-time trace metal monitoring in human sweat.Electrochem Commun2015;51:41-5

[79] Gao W,Nyein HYY.Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis.Nature2016;529:509-14 PMCID:PMC4996079

[80] Abrar MA,Lee PK.Bendable electro-chemical lactate sensor printed with silver nano-particles.Sci Rep2016;6:30565 PMCID:PMC4964653

[81] Imani S,Mohan AMV.A wearable chemical-electrophysiological hybrid biosensing system for real-time health and fitness monitoring.Nat Commun2016;7:11650 PMCID:PMC4879240

[82] Harvey CJ,Stefaniak AB.Formulation and stability of a novel artificial human sweat under conditions of storage and use.Toxicol In Vitro2010;24:1790-6

[83] Liu YL,Qin Y.Flexible electrochemical urea sensor based on surface molecularly imprinted nanotubes for detection of human sweat.Anal Chem2018;90:13081-7

[84] Dang W,Navaraj WT,Vinciguerra V.Stretchable wireless system for sweat pH monitoring.Biosens Bioelectron2018;107:192-202

[85] Sempionatto JR,Ahmed A.Epidermal enzymatic biosensors for sweat vitamin C: toward personalized nutrition.ACS Sens2020;5:1804-13

[86] Xu Z,Lv M,Fan GC.An anti-fouling wearable molecular imprinting sensor based on semi-interpenetrating network hydrogel for the detection of tryptophan in sweat.Anal Chim Acta2023;1283:341948

[87] Sideris GA,Vyllioti AT.The role of branched-chain amino acid supplementation in combination with locoregional treatments for hepatocellular carcinoma: systematic review and meta-analysis.Cancers2023;15:926 PMCID:PMC9913329

[88] Holeček M.Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements.Nutr Metab2018;15:33 PMCID:PMC5934885

[89] Tang W,Sempionatto JR,Teymourian H.Touch-based stressless cortisol sensing.Adv Mater2021;33:2008465

[90] Kamat V,Acosta Y,Mujawar MA.Molecular imprinted polymer-based FET sensor for sensing of sweat testosterone to monitor athletic performance.Meet Abstr2022;MA2022-02:2291

[91] Churcher NK, Upasham S, Rice P, Bhadsavle S, Prasad S. Development of a flexible, sweat-based neuropeptide Y detection platform.RSC Adv2020;10:23173-86 PMCID:PMC9054693

[92] Sonner Z,Heikenfeld J.The microfluidics of the eccrine sweat gland, including biomarker partitioning, transport, and biosensing implications.Biomicrofluidics2015;9:031301 PMCID:PMC4433483

[93] Munje RD,Jagannath B.A new paradigm in sweat based wearable diagnostics biosensors using room temperature ionic liquids (RTILs).Sci Rep2017;7:1950 PMCID:PMC5434046

[94] Marques-Deak A, Cizza G, Eskandari F, et al; Premenopausal, Osteoporosis Women, Alendronate, Depression Study Group. Measurement of cytokines in sweat patches and plasma in healthy women: validation in a controlled study. J Immunol Methods 2006;315:99-109.

[95] Liarte S,Nicolás FJ.Role of TGF-β in skin chronic wounds: a keratinocyte perspective.Cells2020;9:306 PMCID:PMC7072438

[96] Xiao J,Luo Y,Zhang X.Wearable plasmonic sweat biosensor for acetaminophen drug monitoring.ACS Sens2023;8:1766-73

[97] Tai LC,Nyein HYY.Nicotine monitoring with a wearable sweat band.ACS Sens2020;5:1831-7

[98] Xu C,Sempionatto JR.A physicochemical-sensing electronic skin for stress response monitoring.Nat Electron2024;7:168-79 PMCID:PMC10906959

[99] Bandodkar AJ,Ghaffari R.Wearable sensors for biochemical sweat analysis.Annu Rev Anal Chem2019;12:1-22

[100] Ghaffari R,Kim J.State of sweat: emerging wearable systems for real-time, noninvasive sweat sensing and analytics.ACS Sens2021;6:2787-801 PMCID:PMC9108092

[101] Kwon K,Deng Y.An on-skin platform for wireless monitoring of flow rate, cumulative loss and temperature of sweat in real time.Nat Electron2021;4:302-12

[102] Ghaffari R,Raj MS.Soft wearable systems for colorimetric and electrochemical analysis of biofluids.Adv Funct Mater2020;30:1907269

[103] Heng W,Kim WS.Emerging wearable flexible sensors for sweat analysis.Bio-des Manuf2022;5:64-84

[104] Toi PT,Dang TML,Lee NE.Highly electrocatalytic, durable, and stretchable nanohybrid fiber for on-body sweat glucose detection.ACS Appl Mater Interfaces2019;11:10707-17

[105] Saha T,Knisely CT.Wireless wearable electrochemical sensing platform with zero-power osmotic sweat extraction for continuous lactate monitoring.ACS Sens2022;7:2037-48

[106] Huang X,Liu Y.Epidermal self-powered sweat sensors for glucose and lactate monitoring.Bio-des Manuf2022;5:201-9

[107] Parrilla M,Cánovas R,Cuartero M.Wearable potentiometric ion patch for on-body electrolyte monitoring in sweat: toward a validation strategy to ensure physiological relevance.Anal Chem2019;91:8644-51

[108] Zhang X,Wu H,Niu L.Integrated aptasensor array for sweat drug analysis.Anal Chem2022;94:7936-43

[109] Veeralingam S.Two-dimensional metallic NiSe₂ nanoclusters-based low-cost, flexible, amperometric sensor for detection of neurological drug carbamazepine in human sweat samples.Front Chem2020;8:337 PMCID:PMC7205447

[110] Wang S,Yang X.An unconventional vertical fluidic-controlled wearable platform for synchronously detecting sweat rate and electrolyte concentration.Biosens Bioelectron2022;210:114351

[111] Dautta M,Davis N.Tape-free, digital wearable band for exercise sweat rate monitoring.Adv Mater Technol2023;8:2201187

[112] Zhang B,Zhou J.A three-dimensional liquid diode for soft, integrated permeable electronics.Nature2024;628:84-92

[113] Bandodkar AJ,Huang I.Sweat-activated biocompatible batteries for epidermal electronic and microfluidic systems.Nat Electron2020;3:554-62

[114] Brasier N, Sempionatto JR, Bourke S, et al. Towards on-skin analysis of sweat for managing disorders of substance abuse. Nat Biomed Eng 2024.

[115] Sun X,Li H.Wearable near-field communication sensors for healthcare: materials, fabrication and application.Micromachines2022;13:784 PMCID:PMC9146494

[116] Cheng C,Xu G.Battery-free, wireless, and flexible electrochemical patch for in situ analysis of sweat cortisol via near field communication.Biosens Bioelectron2021;172:112782

[117] Lin R,Achavananthadith S.Wireless battery-free body sensor networks using near-field-enabled clothing.Nat Commun2020;11:444 PMCID:PMC6978350

[118] Heikenfeld J.Non-invasive analyte access and sensing through eccrine sweat: challenges and outlook circa 2016.Electroanalysis2016;28:1242-9

[119] Tasangtong B,Hasoon C,Rodthongkum N.Fabrication of biocompatible and biodegradable cloth-based sweat sensors using polylactic acid (PLA) via stencil transparent film-printing.Sensors Actuat B Chem2024;408:135513

[120] Feng X,Wu Z.Defect-enriched graphene nanoribbons tune the adsorption behavior of the mediator to boost the lactate/oxygen biofuel cell.Nanomaterials2023;13:1089 PMCID:PMC10058110

[121] Shitanda I,Niiyama A.High-power lactate/O₂ enzymatic biofuel cell based on carbon cloth electrodes modified with MgO-templated carbon.J Power Sources2019;436:226844

[122] Jia W,Bandodkar AJ,Wang J.Epidermal biofuel cells: energy harvesting from human perspiration.Angew Chem Int Ed Engl2013;52:7233-6

[123] Hartel MC,Weiss PS,Kim J.Resettable sweat-powered wearable electrochromic biosensor.Biosens Bioelectron2022;215:114565

[124] Yu Y,Xu C.Biofuel-powered soft electronic skin with multiplexed and wireless sensing for human-machine interfaces.Sci Robot2020;5:eaaz7946 PMCID:PMC7326328

[125] Shitanda I,Iwashita R.Paper-based lactate biofuel cell array with high power output.J Power Sources2021;489:229533

[126] Shitanda I,Loew N,Itagaki M.High-performance, two-step/Bi-enzyme lactate biofuel cell with lactate oxidase and pyruvate oxidase.J Power Sources2021;498:229935

[127] Chen X,Lv J.Stretchable and flexible buckypaper-based lactate biofuel cell for wearable electronics.Adv Funct Mater2019;29:1905785

[128] Yin L,Sempionatto JR.A passive perspiration biofuel cell: high energy return on investment.Joule2021;5:1888-904

[129] Bandodkar AJ,Kim N.Soft, stretchable, high power density electronic skin-based biofuel cells for scavenging energy from human sweat.Energy Environ Sci2017;10:1581-9

[130] Yang Y,Zhu X,Chen R.Flexible enzymatic biofuel cell based on 1, 4-naphthoquinone/MWCNT-Modified bio-anode and polyvinyl alcohol hydrogel electrolyte.Biosens Bioelectron2022;198:113833

[131] Escalona-villalpando R,Bocanegra-ugalde J,Ledesma-garcía J.Clean energy from human sweat using an enzymatic patch.J Power Sources2019;412:496-504

[132] Escalona-villalpando RA,Milton RD,Minteer SD.Improving the performance of lactate/oxygen biofuel cells using a microfluidic design.J Power Sources2017;342:546-52

[133] Hickey DP,Milton RD.A self-powered amperometric lactate biosensor based on lactate oxidase immobilized in dimethylferrocene-modified LPEI.Biosens Bioelectron2016;77:26-31

[134] Han XF,Wang WT.Templated-assisted synthesis of structurally ordered intermetallic Pt₃Co with ultralow loading supported on 3D porous carbon for oxygen reduction reaction.ACS Appl Mater Interfaces2021;13:37133-41

[135] Zhang W,Fan S,Liu C.Oxygen reduction catalyzed by bilirubin oxidase and applications in biosensors and biofuel cells.Microchem J2022;183:108052

[136] Macedo LJ,Sedenho GC.Three-dimensional catalysis and the efficient bioelectrocatalysis beyond surface chemistry.J Catal2021;401:200-5

[137] Wang J,Pei X.Flexible biofuel cell-in-A-tube (iezTube): an entirely self-contained biofuel cell for wearable green bio-energy harvesting.Adv Funct Mater2022;32:2209697

[138] Yin S,Miyake T.Wearable high-powered biofuel cells using enzyme/carbon nanotube composite fibers on textile cloth.Biosens Bioelectron2019;141:111471

[139] Sun M,Pei X.A flexible and wearable epidermal ethanol biofuel cell for on-body and real-time bioenergy harvesting from human sweat.Nano Energy2021;86:106061

[140] Su Y,Zhou M.Wearable microbial fuel cells for sustainable self-powered electronic skins.ACS Appl Mater Interfaces2022;14:8664-8

[141] Mohammadifar M,Yang JH,Choi S.Biopower-on-skin: electricity generation from sweat-eating bacteria for self-powered e-skins.Nano Energy2020;75:104994

[142] Bae CW,Lee EH.Stretchable non-enzymatic fuel cell-based sensor patch integrated with thread-embedded microfluidics for self-powered wearable glucose monitoring.Adv Mater Inter2022;9:2200492

[143] Eswaran M,Pandit S,Mijakovic I.A flexible multifunctional electrode based on conducting PANI/Pd composite for non-enzymatic glucose sensor and direct alcohol fuel cell applications.Fuel2023;345:128182

[144] Wang C,Chang HK,Kim HR.Sustainable and high-power wearable glucose biofuel cell using long-term and high-speed flow in sportswear fabrics.Biosens Bioelectron2020;169:112652

[145] Ortega L,Esquivel JP.Self-powered smart patch for sweat conductivity monitoring.Microsyst Nanoeng2019;5:3 PMCID:PMC6348283

[146] Ju J,Jian Y.Scalable, high-performance, yarn-shaped batteries activated by an ultralow volume of sweat for self-powered sensing textiles.Nano Energy2023;109:108304

[147] Liu Y,Zhou J.Stretchable sweat-activated battery in skin-integrated electronics for continuous wireless sweat monitoring.Adv Sci2022;9:e2104635 PMCID:PMC8948546

[148] Liu Y,Zhou J.Bandage based energy generators activated by sweat in wireless skin electronics for continuous physiological monitoring.Nano Energy2022;92:106755

[149] Wu M,Zhou J.Bio-inspired ultra-thin microfluidics for soft sweat-activated batteries and skin electronics.J Mater Chem A2022;10:19662-70

[150] Zhao G,Huang X.Soft, sweat-powered health status sensing and visualization system enabled by laser-fabrication.Adv Sensor Res2023;2:2300070

[151] Xiao G,Lu H.A weavable and scalable cotton-yarn-based battery activated by human sweat for textile electronics.Adv Sci2022;9:2103822

[152] Lv J,Li Y.Printable elastomeric electrodes with sweat-enhanced conductivity for wearables.Sci Adv2021;7:eabg8433 PMCID:PMC8279513

[153] Luo Z,Kou B,Zhang W.“Sweat-chargeable” on-skin supercapacitors for practical wearable energy applications.Energy Storage Mater2021;38:9-16

[154] Manjakkal L,Yogeswaran N,Dahiya R.A wearable supercapacitor based on conductive PEDOT:PSS-coated cloth and a sweat electrolyte.Adv Mater2020;32:1907254

[155] Dauzon E,Plesse C,Amassian A.Pushing the limits of flexibility and stretchability of solar cells: a review.Adv Mater2021;33:2101469

[156] Garland NT,Bandodkar AJ.Biofluid-activated biofuel cells, batteries, and supercapacitors: a comprehensive review.Adv Mater2023;35:2303197

[157] Yin L,Lv J.A self-sustainable wearable multi-modular E-textile bioenergy microgrid system.Nat Commun2021;12:1542 PMCID:PMC7943583

[158] Lv J,Tehrani F.Sweat-based wearable energy harvesting-storage hybrid textile devices.Energy Environ Sci2018;11:3431-42

[159] Huang X,Park W.Intelligent soft sweat sensors for the simultaneous healthcare monitoring and safety warning.Adv Healthc Mater2023;12:2202846