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

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.