Micro-Newton Detection by Using Graphene-paper Force Sensor

Abstract

The fabrication of a mechanically flexible piezoresistive load sensor is reported. Inkjet printing offers an inexpensive non-contact fabrication method for microelectronics. Herein we report the first direct fabrication of inkjet-printed graphene arrays, and apply them to electromechanical detection of force. The graphene ink was printed on a cantilever shape paper substrate. The results illustrated a linear resistance change with the applied forces. The force range, force resolution, and sensitivity were found to be 25 mN, 10 μN, and 1.2 mV/mN, respectively. In addition, graphite ink was also used as the sensing component in order to make a comparison between the piezoresistive effect of graphene and graphite ink. The results show that using graphene ink instead of graphite increases the force range and gauge factor of the sensor, which are two important designing factors. This sensor is inexpensive, simple to fabricate, lightweight, and disposable.