Engineered Microstructure Derived Hierarchical Deformation of Flexible Pressure Sensor Induces a Supersensitive Piezoresistive Property in Broad Pressure Range

ABSTRACT: Abstract Fabricating flexible pressure sensors with high sensitivity in a broad pressure range is still a challenge. Herein, a flexible pressure sensor with engineered microstructures on polydimethylsiloxane (PDMS) film is designed. The high performance of the sensor derives from its unique pyramid?wall?grid microstructure (PWGM). A square array of dome?topped pyramids and crossed strengthening walls on the film forms a multiheight hierarchical microstructure. Two pieces of PWGM flexible PDMS film, stacked face?to?face, form a piezoresistive sensor endowed with ultrahigh sensitivity across a very broad pressure range. The sensitivity of the device is as high as 383 665.9 and 269 662.9 kPa?1 in the pressure ranges 0–1.6 and 1.6–6 kPa, respectively. In the higher pressure range of 6.1–11 kPa, the sensitivity is 48 689.1 kPa?1, and even in the very high pressure range of 11–56 kPa, it stays at 1266.8 kPa?1. The pressure sensor possesses excellent bending and torsional strain detection properties, is mechanically durable, and has potential applications in wearable biosensing for healthcare. In addition, 2 × 2 and 4 × 4 sensor arrays are prepared and characterized, suggesting the possibility of manufacturing a flexible tactile sensor. A flexible piezoresistive pressure sensor with hierarchical microstructures on its interlocked polydimethylsiloxane sensing films is fabricated by using a specially designed silicon template with the unique pyramid?wall grid microstructures of different height and a four?step mold?casting process. The sensor has ultrahigh sensitivity in a very wide pressure range, yielding better performance than most flexible pressure sensor in literature.

SUBMITTER: Li G 

PROVIDER: S-EPMC7509712 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature