A Solution-Processable, Omnidirectionally Stretchable, and High-Pressure-Sensitive Piezoresistive Device

Abstract

The development of omnidirectionally stretchable pressure sensors with high performance without stretching-induced interference has been hampered by many challenges. Herein, an omnidirectionally stretchable piezoresistive pressure-sensing device is demonstrated by combining an omniaxially stretchable substrate with a 3D micropattern array and solution-printing of electrode and piezoresistive materials. A unique substrate structural design and materials mean that devices that are highly sensitive are rendered, with a stable out-of-plane pressure response to both static (sensitivity of 0.5 kPa⁻¹ and limit of detection of 28 Pa) and dynamic pressures and the minimized in-plane stretching responsiveness (a small strain gauge factor of 0.17), achieved through efficient strain absorption of the electrode and sensing materials. The device can detect human-body tremors, as well as measure the relative elastic properties of human skin. The omnidirectionally stretchable pressure sensor with a high pressure sensitivity and minimal stretch-responsiveness yields great potential to skin-attachable wearable electronics, human–machine interfaces, and soft robotics applications.

An omnidirectionally stretchable piezoresistive pressure-sensing device is realized by combining a stress-relieving and omniaxially stretchable substrate having regular 3D micropattern arrays with a solution-processed silver-paste electrode and a piezoresistive nanocomposite. This enables highly sensitive pressure responses while the in-plane stretching responsivity is minimized. The device is demonstrated to detect body tremors and measure the relative elastic properties of human skin.

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