Scalable fabrication of flexible piezoresistive pressure sensors based on occluded microstructures for subtle pressure and force waveform detection

Scalable, economical, simple, time-saving, and eco-friendly fabrication of flexible pressure sensors is a big thrust for developing flexible sensors/electronics, while it is a current challenge to fabricate subtle pressure-sensitive sensors in such a way. Here, we report an occluded flexible piezoresistive pressure sensor with the foregoing features using a conventional polymer processing method. Poly(dimethyl siloxane)/carbon nanostructure (PDMS/CNS) composite film pressure sensors with tailorable microstructures were prepared using commercially available metal sieve templates with a transfer printing method. Acquiring an appropriate occluded configuration with face-to-face microstructures, the derived sensor displays high pressure sensitivity (1.214 kPa-1) under subtle pressure (<100 Pa), an ultralow detection limit (1.75 Pa), a rapid response, a super-low working voltage (0.1 V), and excellent sensing stability for more than 1700 cycles. The pressure sensor with programmable size, shape and sensitivity is capable of discriminating varied forms and frequencies of input pressure signals with instant and precise response, enabling potential application in flexible electronics.