Direct-Write Fabrication of Flexible Array Pressure Sensor for Monitoring Position Distribution

Abstract

Tactile sensors with high flexibility have attracted great interest because of their huge potential in various applications including smart robots, smart prostheses, human-machine interfaces, and biological monitoring electronic devices. However, it remains a critical challenge to develop tactile sensors with both high sensitivity and flexibility. In this work, a flexible 8 × 8 array pressure sensors with GNPs/MWCNT filled conductive composite material on PDMS substrates was proposed using direct-write printing. The printing technology based on the Weissenberg effect had the advantages of rapid supply of fluid and avoiding needle clogging in the printing process, which was suitable for large-area manufacturing of sensor sensitive units. The sensitivity of PDMS-based flexible array pressure sensors in the pressure range of 0–25 kPa and 25–75 kPa reached ∼5.09 MPa−1 and ∼0.0209 kPa−1, respectively. Response/recovery time reached ∼150 ms and ∼200 ms, respectively. When 1000 cycles were performed in the 0–75 kPa pressure range, the PDMS substrate flexible array pressure sensor had high stability and repeatability. These superior properties are indicative of their great potential in applications such as intelligent robotics, artificial palpation, prosthetics, and wearable devices.

Direct ink write printing of resistive-type humidity sensors

“…a few to hundreds of micrometers is more reliable to print viscous polymeric ink or particle containing ink. Recent developments have reported the DIW printing of functional structures like conductive electrodes [37], energy storage devices [41], 3D inductors [39] and pressure sensor arrays [42]. Its automatic controlled operation clearly brings the advantages of high efficiency, reproducibility and accuracy when compared with drop casting or brush painting of sensing materials that often used in the research of humidity sensors [43,44].…”