Gradient expanded-structured graphene pressure sensor prepared by one-step laser reduction with superhigh sensitivity and ultrawide detection range

With the advancement of information data, intelligent devices have put forward higher performance requirements for pressure sensors. Reasonable structural design of active material provides an effective way for the preparation of high-performance pressure sensor. Herein, we propose a simple method to prepare gradient expandion-structured graphene-based flexible pressure sensors by laser reduction. There are many gas gaps exist under the graphene surface, showing a certain gradient as a whole. Benefiting from the synergy effect of the unique structure, the designed piezoresistive sensor shows high sensitivity (127.8 kPa(-1) in the range of 0.33-0.667 kPa), broad linear range (0-16.7 kPa), low detection limit (33 Pa), short response time (200 ms), and good stability (more than 7000 cycles). Furthermore, the notion of creating and constructing gradient structures has been applied to practical applications of position sensing, and possible applications for mapping the position and intensity of pressure have also been investigated.