Human Skin-Inspired Flexible Pressure Sensor with Multi-Modulus Porous Structure

초록

Despite significant advances being made in pressure sensor technologies, driven by increasing demand for wearable devices, future Internet of Things (IoT) applications, and electronic skin (e-skin), critical challenges persist in achieving high sensitivity, high pressure resolution, rapid response, and a wide linear range. Here, we report a cost-effective and easy-to-fabricate pressure sensor that simultaneously achieves high sensitivity and an extensive linear operating range by emulating the multi-modulus structure of human skin. Typically, these two properties are inversely related, rendering their simultaneous optimization highly challenging. Our sensor design employs a porous structure, composed of two layers of distinct moduli; this is achieved by precisely adjusting the base to crosslinker ratio of polydimethylsiloxane mixed with multi-walled carbon nanotubes (MWCNTs). The synergistic effect of the MWCNTs and porous structure results in a high sensitivity (2.24 kPa- 1), while the dual-modulus configuration extends the linear response (up to 45 kPa). Moreover, the sensor demonstrates excellent reproducibility and can maintain a stable response even after 6000 cycles of mechanical deformation at 15 kPa. These findings underscore the sensor's efficacy in diverse pressure detection scenarios and its potential for applications in human-machine interface systems and soft robotics.

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