Dual‐Scale Porous Composite for Tactile Sensor with High Sensitivity over an Ultrawide Sensing Range. Issue 39 (15th August 2022)

• Record Type: Journal Article
• Authors: Bae, Kyubin; Kim, Minhyeong; Kang, Yunsung; Sim, Sangjun; Kim, Wondo; Pyo, Soonjae; Kim, Jongbaeg
• Is Part Of: Small. Volume 18:Issue 39(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-15
• Subjects: high sensitivity -- human‐motion detection -- large sensing range -- porous structure -- tactile sensors; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202203193
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Porous structures have been utilized in tactile sensors to improve sensitivity owing to their excellent deformability. Recently, tactile sensors using porous structures have been used in practical applications, such as bio‐signal monitoring. However, highly sensitive responses are limited to the low‐pressure range, and their sensitivity significantly decreases in a higher‐pressure range. Several approaches for developing tactile sensors with high sensitivity overing a wide pressure range have been proposed; however, achieving high sensitivity and wide sensing range remains a crucial challenge. This report presents a carbon nanotube (CNT)‐coated CNT–polydimethylsiloxane (PDMS) composite having dual‐scale pores for tactile sensors with high sensitivity over a wide pressure range. The porous polymer frame formed with dense pores of dual sizes facilitates the closure of large and small pores at low and high pressures, respectively. This results in an apparent increase in the number of contact points between the CNT–CNT at the pores even under a wide pressure range. Furthermore, the piezoresistivity of the CNT–PDMS composite contributes to achieving a high sensitivity of the tactile sensor over a wide pressure range. Based on these mechanisms, various human movements over a broad pressure spectrum are monitored to investigate the practical usefulness of the sensor. Abstract : A resistive tactile sensor based on carbon nanotube‐embedded/‐coated dual‐scale porous structure is presented. The sensor exhibits a highly sensitive and linear response over an ultrawide detection range while presenting stability, repeatability, flexibility, low limit of detection, and mechanical durability. Moreover, various human movements ranging from breath to foot pressure are successfully monitored.