Paper-Based Sensor with Bioinspired Macrogrooves for Dual Pressure and Mechanical Strain Signal Detection

Flexible and wearable sensors are of paramount importance in applications like electronic skin, health monitoring, and human-computer interactions. However, mass production of flexible sensors with versatile, high-performance, low-cost, and easy-to-dispose features remains a huge challenge. Herein, based on a strategy of bionics inspired by the slit receptors in arthropods, a flexible paper-based sensor with macrocracks is developed. And a large number of irregular microdomes are formed on the surfaces of folded paper, which attributes to the conductive composites constructed by carbon nanomaterials and poly(dimethylsiloxane) (PDMS). Macrocracks and microdomes are helpful to achieve outstanding dual mechanical strain/pressure signal sensing functions. The materials used and the fabricating method employed are cost-efficient and convenient. As a result, the paper-based sensor exhibits a gauge factor of 64 within the strain range of 1% and excellent stability over 1500 cycles. When serving as a pressure sensor, it shows a high sensitivity of 1.4 kPa-1 in the range within 0.5 kPa. Also, the paper-based sensor shows an environmentally friendly feature and can be almost disposed of naturally, indicating that the bioinspired sensor could serve as disposable green flexible electronics, which has potential usage in wearable applications.