A graphene flexible pressure sensor based on a fabric-like groove structure for high-resolution tactile imaging

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-09, Vol.495, p.153281, Article 153281
• Main Authors: Tang, Xinyue, Yang, Jun, Luo, Jiayuan, Cheng, Guanyin, Sun, Bihao, Zhou, Zhen, Zhang, Peijian, Wei, Dapeng
• Format: Article
• Language: English
• Subjects: Artificial intelligence; E-skin; Graphene; Piezoresistive sensor; Robotics
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.153281

This work introduces a Graphene fabric-like groove pattern for flexible piezoresistive sensors. This unique strcture allows the sensor to maintain a high linearity and high sensitivity over a wide pressure range. The GNWs groove piezoresistive sensor exhibits unprecedented sensitivity (S= 2297.47 kPa−1) over an extensive pressure range (0.2 Pa − 425 kPa). Base on the GNWs groove sensor we built a high-resolution tactile imaging system which can reconstruct the texture of a leaf and reconstruct the shape of letters under soft elastomer. [Display omitted] •This work introduces a conformal GNWs fabric-like groove structure for flexible piezoresistive sensors.•The GNWs groove sensor exhibits high sensitivity (S = 2297.47 kPa−1) over an extensive pressure range (0.2 Pa − 425 kPa).•A high-resolution tactile imaging system was built.•3D reconstruction of leaf surface texture owns a surface height resolution of 20 μm.•Tactile imaging system is capable of distinguishing elastic films with a thickness as small as 0.1 mm. Flexible pressure sensors hold significant promise for applications in fields such as prosthetics, electronic skin, robotics, and healthcare. Nevertheless, the challenge lies in preserving the linear sensitivity range of these sensors across a broad pressure range. In this study, we introduce a structure featuring Graphene Nano-walls (GNWs) arranged in a fabric-like groove pattern for flexible piezoresistive sensors. This design effectively accommodates material deformations, enabling the sensor to maintain exceptional sensitivity across a wide pressure range. The GNWs groove piezoresistive sensor exhibits ultra-high sensitivity (S = 2297.47 kPa−1) and outstanding linearity (R2 = 0.986) over an extensive pressure range (0.2 Pa − 425 kPa), while maintaining remarkable mechanical stability over 10,000 cycles. It boasts rapid response times of 9 ms and a recovery time of 7 ms. Owing to the fast response and high sensitivity of this sensor, we constructed a high-resolution tactile imaging system, with a surface height resolution of 20 μm and a elastic film thickness resolution of 0.1 mm. Noteworthy, we reconstructed the 3D texture of a leaf and reconstructed the shape of letters under soft elastomer. These applications underscore the potential of GNWs groove pressure sensors in various fields, including artificial intelligence, robotics, prosthetics, and so on.