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.