Flexible pressure sensor with tunable sensitivity and responsive range for adaptive wearable electronics

Abstract

Flexible pressure sensors are a key component of electronic skins (e-skins), converting mechanical stimuli into easily analyzed electrical signals. These sensors need to be highly sensitive to respond to small changes in external stimuli. However, balancing the trade-off between sensitivity and pressure monitoring range remains a significant challenge. Here, we fabricated a capacitive tunable pressure sensor (TPS), based on the synergistic effect within a composite material, composed of a sponge-like porous structure and thermoplastic expandable microspheres (TEMs). By adjusting the temperature to drive the expansion of the TEMs, mode switching between low and high compression modulus was achieved. This enables high sensitivity (2.39 kPa⁻¹) in low compression modulus mode and a wide pressure monitoring range (up to 953.96 kPa) in high compression modulus mode. TPSs are applicable in diverse fields, from detecting subtle pressures like human pulse and respiration to measuring larger pressures based on touch, and even vehicle loads. These sensors can also be integrated with machine learning algorithms for object recognition. The success of TPS is expected to provide new ideas in solving the trade-off between sensitivity and pressure monitoring range of flexible pressure sensors.

Keywords

flexible pressure sensor / heat-driven expansion / porous structure / thermoplastic expandable microspheres (TEMs) / tunable modulus

References

[1] Lee S, Franklin S, Hassani FA, et al. Nanomesh pressure sensor for monitoring finger manipulation without sensory interference. Science. 2020;370(6519):966-970.

[2] Song J, Yang R, Shi J, et al. Polyelectrolyte-based wireless and drift-free iontronic sensors for orthodontic sensing. Sci Adv. 2025;11(11):eadu6086.

[3] Araromi OA, Graule MA, Dorsey KL, et al. Ultra-sensitive and resilient compliant strain gauges for soft machines. Nature. 2020;587(7833):219-224.

[4] Luo Y, Abidian MR, Ahn J-H, et al. Technology roadmap for flexible sensors. ACS Nano. 2023;17(6):5211-5295.

[5] Ha K-H, Huh H, Li Z, Lu N. Soft capacitive pressure sensors: trends, challenges, and perspectives. ACS Nano. 2022;16(3):3442-3448.

[6] Ding Y, Jiang J, Wu Y, et al. Porous conductive textiles for wearable electronics. Chem Rev. 2024;124(4):1535-1648.

[7] Duan S, Yang H, Hong J, et al. A skin-beyond tactile sensor as interfaces between the prosthetics and biological systems. Nano Energy. 2022;102:107665.

[8] Su Q, Zou Q, Li Y, et al. A stretchable and strain-unperturbed pressure sensor for motion interference–free tactile monitoring on skins. Sci Adv. 2021;7(48):eabi4563.

[9] Ma Y, Zhang Y, Cai S, et al. Flexible hybrid electronics for digital healthcare. Adv Mater. 2020;32:1902062.

[10] Jiang Z, Zhu M, Chen X. Interfacing neuron-motor pathways with stretchable and biocompatible electrode arrays. Acc Chem Res. 2024;57(16):2255-2266.

[11] Lv C, Tian C, Jiang J, et al. Ultrasensitive linear capacitive pressure sensor with wrinkled microstructures for tactile perception. Adv Sci. 2023;10(14):2206807.

[12] Yang L, Wang H, Yuan W, et al. Wearable pressure sensors based on MXene/tissue papers for wireless human health monitoring. ACS Appl Mater Interfaces. 2021;13(50):60531-60543.

[13] Li Y, Yang L, Deng S, et al. A machine learning-assisted multifunctional tactile sensor for smart prosthetics. InfoMat. 2023;5(9):e12463.

[14] He Y, Cheng Y, Yang C, Guo CF. Creep-free polyelectrolyte elastomer for drift-free iontronic sensing. Nat Mater. 2024;23(8):1107-1114.

[15] Yang J-S, Chung M-K, Yoo J-Y, et al. Interference-free nanogap pressure sensor array with high spatial resolution for wireless human–machine interfaces applications. Nat Commun. 2025;16(1):2024.

[16] Zheng Q, Dai X, Wu Y, et al. Self-powered high-resolution smart insole system for plantar pressure mapping. BMEMat. 2023;1(1):e12008.

[17] Shi J, Xie S, Liu Z, Cai M, Guo CF. Non-hygroscopic ionogel-based humidity-insensitive iontronic sensor arrays for intra-articular pressure sensing. Natl Sci Rev. 2024;11(11):nwae351.

[18] Luo L, Gao J, Zheng L, et al. Ultra-low power consumption flexible sensing electronics by dendritic bilayer MoS. InfoMat. 2024;6:e12605.

[19] Yuan H, Zhang Q, Zhou T, et al. Progress and challenges in flexible capacitive pressure sensors: microstructure designs and applications. Chem Eng J. 2024;485:149926.

[20] Mannsfeld SCB, Tee BC-K, Stoltenberg RM, et al. Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers. Nat Mater. 2010;9(10):859-864.

[21] Gong S, Schwalb W, Wang Y, et al. A wearable and highly sensitive pressure sensor with ultrathin gold nanowires. Nat Commun. 2014;5(1):3132.

[22] Zhu D, Duan S, Liu J, et al. A double-crack structure for bionic wearable strain sensors with ultra-high sensitivity and a wide sensing range. Nanoscale. 2024;16(10):5409-5420.

[23] Lee S, Byun S-H, Kim CY, et al. Beyond human touch perception: an adaptive robotic skin based on gallium microgranules for pressure sensory augmentation. Adv Mater. 2022;34:2204805.

[24] Yao H, Yang W, Cheng W, et al. Near–hysteresis-free soft tactile electronic skins for wearables and reliable machine learning. Proc Natl Acad Sci. 2020;117(41):25352-25359.

[25] Niu H, Li N, Kim E-S, et al. Advances in advanced solution-synthesis-based structural materials for tactile sensors and their intelligent applications. InfoMat. 2024;6(1):e12500.

[26] Yuan Y, Liu B, Adibeig MR, et al. Microstructured polyelectrolyte elastomer-based ionotronic sensors with high sensitivities and excellent stability for artificial skins. Adv Mater. 2024;36(11):2310429.

[27] Xiong Y, Shen Y, Tian L, et al. A flexible, ultra-highly sensitive and stable capacitive pressure sensor with convex microarrays for motion and health monitoring. Nano Energy. 2020;70:104436.

[28] Hwang J, Kim Y, Yang H, Oh JH. Fabrication of hierarchically porous structured PDMS composites and their application as a flexible capacitive pressure sensor. Compos Part B Eng. 2021;211:108607.

[29] Huang X, Liu L, Lin YH, et al. High-stretchability and low-hysteresis strain sensors using origami-inspired 3D mesostructures. Sci Adv. 2023;9(34):eadh9799.

[30] Lu P, Wang L, Zhu P, et al. Iontronic pressure sensor with high sensitivity and linear response over a wide pressure range based on soft micropillared electrodes. Sci Bull. 2021;66(11):1091-1100.

[31] Yang R, Dutta A, Li B, et al. Iontronic pressure sensor with high sensitivity over ultra-broad linear range enabled by laser-induced gradient micro-pyramids. Nat Commun. 2023;14(1):2907.

[32] Liang C, Sun J, Liu Z, et al. Wide range strain distributions on the electrode for highly sensitive flexible tactile sensor with low hysteresis. ACS Appl Mater Interfaces. 2023;15(12):15096-15107.

[33] Xie X, Wang Q, Zhao C, et al. Neuromorphic computing-assisted triboelectric capacitive-coupled tactile sensor array for wireless mixed reality interaction. ACS Nano. 2024;18(26):17041-17052.

[34] Ji B, Zhou Q, Hu B, Zhong J, Zhou J, Zhou B. Bio-inspired hybrid dielectric for capacitive and triboelectric tactile sensors with high sensitivity and ultrawide linearity range. Adv Mater. 2021;33:2100859.

[35] Zhang W, Gu G, Ren H, et al. A real-time self-powered wireless pressure sensing system based on capacitive triboelectric pressure sensor. Nano Energy. 2025;136:110729.

[36] Chen R, Luo T, Wang J, et al. Nonlinearity synergy: an elegant strategy for realizing high-sensitivity and wide-linear-range pressure sensing. Nat Commun. 2023;14(1):6641.

[37] Zhou D, Zhang Z, Li Y, Ma T, He H, Li H. Intelligent textiles make life wirelessly energetic by coupling radiation energy and human. BMEMat. 2024;2(2):e12090.

[38] Liu Y, Zhong Z, Liang C, et al. Highly compressive aerogel-elastomer hybrid porous material with redistributed strain for high-sensitive soft pressure sensors. Chem Eng J. 2024;496:154069.

[39] He J, Wang S, Han R, et al. Wide detection range flexible pressure sensors based on 3D interlocking structure TPU/ZnO NWs. Adv Funct Mater. 2025;35(15):2418791.

[40] Feng Z-P, Hao Y-N, Qin J, et al. Ultrasmall barium titanate nanoparticles modulated stretchable dielectric elastomer sensors with large deformability and high sensitivity. InfoMat. 2023;5(8):e12413.

[41] Li M, Hou Z, Mou Y, et al. Bioinspired programmable cilia array for enhanced tactile perception. Nano Energy. 2025;139:110924.

[42] Baek J, Zhang Y, Qin F, et al. Design rules for 3D printing-assisted pressure sensor manufacturing: achieving broad pressure range linearity. Adv Funct Mater. 2025;35(4):2414050.

[43] Zhou Y, Guo S, Zhou Y, et al. Ionic composite nanofiber membrane-based ultra-sensitive and anti-interference flexible pressure sensors for intelligent sign language recognition. Adv Funct Mater. 2025;35(29):2425586.

[44] Cui Z, Hua Q, Shi Y, et al. Skin-integrated haptic interface system based on a stretchable pressure sensor array for wireless tactile visualization applications. Nano Energy. 2025;139:110911.

[45] Li Y, Zhang W, Zhao C, et al. Breaking the saturation of sensitivity for ultrawide range flexible pressure sensors by soft-strain effect. Adv Mater. 2024;36:2405405.

[46] Zhang J, Wu J, Liu L, et al. Converting static to dynamic: biomimetic ultra-sensitive wide-range flexible pressure sensor inspired by the Contact-Regulation process of scorpion pectines. Chem Eng J. 2025;511:162055.

[47] Song L, Wang Z, Chen S, Shen Y, Yin J, Wang R. Phytic acid-induced gradient hydrogels for highly sensitive and broad range pressure sensing. Adv Mater. 2025;37(9):2417978.

[48] Chen Y, Feng T, Peng M, Qin F. Ultra-high filling ratio of non-percolative rapeseed-shaped liquid metal fiber mats for pressure sensors via electrospinning aided inhomogeneous dispersion. Adv Fiber Mater. 2025;7(2):633-644.

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2025 The Author(s). InfoMat published by UESTC and John Wiley & Sons Australia, Ltd.