Structure-Driven, Flexible, Multilayered, Paper-Based Pressure Sensor for Human–Machine Interfacing

Flexible pressure sensors have gained considerable attention for their potential applications in wearable electronics and human-machine interfacing. However, two major bottlenecks in their widespread usage (i) achieving high sensitivity over a wide working pressure range and (ii) constituent material platform for manufacturability and environmental safety still limits its utility. Herein, we suggest a low-cost hierarchical construction strategy, which enhances the sensitivity of a paper-based piezoresistive pressure sensor over a wide working range. This strategy uses a special multilayered cellulose paper structure composed of alternate layers of plain and corrugated paper sheets, coated with 2D tin-monosulfide (SnS). This design of the paper pressure sensor allows it to achieve high sensitivity up to 14.8 kPa-1 and a broad working range of 0-120 kPa with good durability and repeatability. Further, to confirm practical applicability, we utilized an array of these multilayered flexible pressure sensors for monitoring human activity and developing a biodegradable and foldable keypad. The proposed paper-based green electronic platform can potentially be used in a variety of applications including healthcare and human-machine interfacing.