Abstract
The characteristics of real-time monitoring and flexible integration based on passive capacitive detection are becoming the preferred sensing strategy for wearable devices. However, the currently designed capacitive sensors mostly focused on the bionic microstructures to improve sensitivity and measurement accuracy, while ignoring the inherent mechanical wear and resistance of multilayer structures. In this paper, an integrated monolithic capacitive pressure detection based on room temperature liquid metal is designed and fabricated, avoiding the tightness problem of the multi-layer structure. The oxidized paste-like liquid metal owning superior interfacial wetting properties can stably adhere to the surface of the porous framework. The gas-filled porous framework endows the capacitive sensor with a mechanical response of 0.0557 g with a response and recovery time of 1.26 and 0.63 s under a load condition of 150 Pa, and steadily maintained in 1600 cycle tests. Finally, the capacitive sensor is employed to detect human physiological signals and force shock responses, which could clearly distinguish different action signals, providing a new platform for the subsequent development and design of integrated capacitive sensors.
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Guo X, Zhou D, Hong W, et al. Biologically emulated flexible sensors with high sensitivity and low hysteresis: Toward electronic skin to a sense of touch. Small, 2022, 18: 2203044
Li S, Zhang Y, Liang X, et al. Humidity-sensitive chemoelectric flexible sensors based on metal-air redox reaction for health management. Nat Commun, 2022, 13: 5416
Yang Z, Yang D, Zhao X, et al. From liquid metal to stretchable electronics: Overcoming the surface tension. Sci China Mater, 2022, 65: 2072–2088
Sun X, Wang X, Yuan B, et al. Liquid metal-enabled cybernetic electronics. Mater Today Phys, 2020, 14: 100245
Wang X, Fan L, Zhang J, et al. Printed conformable liquid metal e-skin-enabled spatiotemporally controlled bioelectromagnetics for wireless multisite tumor therapy. Adv Funct Mater, 2019, 29: 1907063
Lei M, Feng K, Ding S, et al. Breathable and waterproof electronic skin with three-dimensional architecture for pressure and strain sensing in nonoverlap** mode. ACS Nano, 2022, 16: 12620–12634
Ding L, Xuan S, Pei L, et al. Stress and magnetic field bimode detection sensors based on flexible CI/CNTs-PDMS sponges. ACS Appl Mater Interfaces, 2018, 10: 30774–30784
Wang N, Sun H, Yang X, et al. Flexible temperature sensor based on rGO/CNTs@PBT melting blown nonwoven fabric. Sens Actuat A-Phys, 2022, 339: 113519
Ferrier D C, Honeychurch K C. Carbon nanotube (CNT)-based biosensors. Biosensors, 2021, 11: 486
Ates H C, Nguyen P Q, Gonzalez-Macia L, et al. End-to-end design of wearable sensors. Nat Rev Mater, 2022, 7: 887–907
Nag A, Simorangkir R B V B, Gawade D R, et al. Graphene-based wearable temperature sensors: A review. Mater Des, 2022, 221: 110971
**a S, Wang M, Gao G. Preparation and application of graphene-based wearable sensors. Nano Res, 2022, 15: 9850–9865
** C, Bai Z. Mxene-based textile sensors for wearable applications. ACS Sens, 2022, 7: 929–950
**n M, Li J, Ma Z, et al. Mxenes and their applications in wearable sensors. Front Chem, 2020, 8: 297
Wang Z, Liu Y, Zhang D, et al. Tough, stretchable and self-healing C-Mxenes/PDMS conductive composites as sensitive strain sensors. Compos Sci Tech, 2021, 216: 109042
Lin X, Xue H, Li F, et al. All-nanofibrous ionic capacitive pressure sensor for wearable applications. ACS Appl Mater Interfaces, 2022, 14: 31385–31395
Frediani G, Vannetti F, Bocchi L, et al. Monitoring flexions and torsions of the trunk via gyroscope-calibrated capacitive elastomeric wearable sensors. Sensors, 2021, 21: 6706
Ji B, Zhou Q, Chen G, et al. In situ assembly of a wearable capacitive sensor with a spine-shaped dielectric for shear-pressure monitoring. J Mater Chem C, 2020, 8: 15634–15645
Cicek M O, Doganay D, Durukan M B, et al. Seamless monolithic design for foam based, flexible, parallel plate capacitive sensors. Adv Mater Technologies, 2021, 6: 2001168
Wen L, Nie M, Chen P, et al. Wearable multimode sensor with a seamless integrated structure for recognition of different joint motion states with the assistance of a deep learning algorithm. Microsyst Nanoeng, 2022, 8: 24
Zhang S, Zong Z, Guo C F, et al. Partial liquid alloy microdroplet sedimentation induced a gradient porous structured elastomer with a tunable property for an anisotropic robotic bulk. ACS Appl Mater Interfaces, 2022, 14: 50079–50089
Daeneke T, Khoshmanesh K, Mahmood N, et al. Liquid metals: Fundamentals and applications in chemistry. Chem Soc Rev, 2018, 47: 4073–4111
Yang L X, Zhao X, Xu S, et al. Oxide transformation and break-up of liquid metal in boiling solutions. Sci China Tech Sci, 2019, 63: 289–296
Chen S, Wang H Z, Zhao R Q, et al. Liquid metal composites. Matter, 2020, 2: 1446–1480
Zhang M, Wang X, Huang Z, et al. Liquid metal based flexible and implantable biosensors. Biosensors, 2020, 10: 170
Liang S T, Wang H Z, Liu J. Spray printing and encapsulated liquid metal as a highly reflective metallic paint for packing products. Sci China Tech Sci, 2019, 62: 1577–1584
Fu J H, Zhang X D, Qin P, et al. Sequential oxidation strategy for the fabrication of liquid metal electrothermal thin film with desired printing and functional property. Micromachines, 2021, 12: 1539
Ding Y, Zeng M, Fu L. Surface chemistry of gallium-based liquid metals. Matter, 2020, 3: 1477–1506
Gan T, **ao Q, Handschuh-Wang S, et al. Conformally adhesive, large-area, solidlike, yet transient liquid metal thin films and patterns via gelatin-regulated droplet deposition and sintering. ACS Appl Mater Interfaces, 2022, 14: 42744–42756
Guo J, Cheng J, Wang S, et al. A protective FeGa3 film on the steel surface prepared by in-situ hot-reaction with liquid metal. Mater Lett, 2018, 228: 17–20
Zhang S, Wang B, Jiang J, et al. High-fidelity conformal printing of 3D liquid alloy circuits for soft electronics. ACS Appl Mater Interfaces, 2019, 11: 7148–7156
Zhang S, Jiang J, Jiang Q, et al. Dynamically conformal mask printing of liquid alloy circuits on morphing objects. Adv Mater Technologies, 2021, 6: 2001274
Jiang J, Fei W, Pu M, et al. A facile liquid alloy wetting enhancing strategy on super-hydrophobic lotus leaves for plant-hybrid system implementation. Adv Mater Inter, 2022, 9: 2200516
Gao J Y, Zhang X D, Fu J H, et al. Numerical investigation on integrated thermal management via liquid convection and phase change in packed bed of spherical low melting point metal macrocapsules. Int J Heat Mass Transfer, 2020, 150: 119366
Yu D H, He Z Z. Shape-remodeled macrocapsule of phase change materials for thermal energy storage and thermal management. Appl Energy, 2019, 247: 503–516
Zhang X D, Yang X H, Zhou Y X, et al. Experimental investigation of galinstan based minichannel cooling for high heat flux and large heat power thermal management. Energy Convers Manage, 2019, 185: 248–258
Wang D, Rao W. Numerical simulation on thermal response of laser-irradiated biological tissues embedded with liquid metal nanoparticles. J Therm Sci, 2022, 31: 1220–1235
Alsaif M M Y A, Pillai N, Kuriakose S, et al. Atomically thin Ga2S3 from skin of liquid metals for electrical, optical, and sensing applications. ACS Appl Nano Mater, 2019, 2: 4665–4672
Shengurov V G, Denisov S A, Chalkov V, et al. Gallium-doped germanium epitaxial layers grown on silicon substrates by hot wire chemical vapor deposition. Mater Sci Eng-B, 2020, 259: 114579
Wang Y, Wang S, Chang H, et al. Galvanic replacement of liquid metal/reduced graphene oxide frameworks. Adv Mater Interfaces, 2020, 7: 2000626
Chen S, Wang H Z, Sun X Y, et al. Generalized way to make temperature tunable conductor-insulator transition liquid metal composites in a diverse range. Mater Horiz, 2019, 6: 1854–1861
Chang H, Guo R, Sun Z, et al. Direct writing and repairable paper flexible electronics using nickel-liquid metal ink. Adv Mater Interfaces, 2018, 5: 1800571–1800581
Chang H, Zhang P, Guo R, et al. Recoverable liquid metal paste with reversible rheological characteristic for electronics printing. ACS Appl Mater Interfaces, 2020, 12: 14125–14135
Guo R, Wang X, Chang H, et al. Ni-GaIn amalgams enabled rapid and customizable fabrication of wearable and wireless healthcare electronics. Adv Eng Mater, 2018, 20: 1800054–1800062
Zhai Y, Yu Y, Zhou K, et al. Flexible and wearable carbon black/thermoplastic polyurethane foam with a pinnate-veined aligned porous structure for multifunctional piezoresistive sensors. Chem Eng J, 2020, 382: 122985
Tay R Y, Li H, Lin J, et al. Lightweight, superelastic boron nitride/polydimethylsiloxane foam as air dielectric substitute for multifunctional capacitive sensor applications. Adv Funct Mater, 2020, 30: 1909604
Chortos A, Bao Z. Skin-inspired electronic devices. Mater Today, 2014, 17: 321–331
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This work was supported by the National Natural Science Foundation of China (Grant No. 21805294).
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Fu, JH., Zhan, F., **ng, Z. et al. Oxidating liquid metal interface integrated capacitive pressure detection. Sci. China Technol. Sci. 66, 1629–1639 (2023). https://doi.org/10.1007/s11431-022-2357-x
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DOI: https://doi.org/10.1007/s11431-022-2357-x