Crocodile‐Skin‐Inspired Omnidirectionally Stretchable Pressure Sensor. Issue 52 (3rd November 2022)

• Record Type: Journal Article
• Authors: Lee, Giwon; Son, Jonghyun; Kim, Daegun; Ko, Hyeon Ju; Lee, Seung Goo; Cho, Kilwon
• Is Part Of: Small. Volume 18:Issue 52(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-11-03
• Subjects: crocodile skin -- electronic skin -- pressure sensors -- stretchable -- wrinkles; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.202205643
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: Stretchable pressure sensors are important components of multimodal electronic skin needed for potentializing numerous Internet of Things applications. In particular, to use pressure sensors in various wearable/skin‐attachable electronics, both high deformability and strain‐independent sensitivity must be realized. However, previously reported stretchable pressure sensors cannot meet these standards because they exhibit limited stretchability and nonuniform sensitivity under deformation. Herein, inspired by the unique sensory organ of a crocodile, an omnidirectionally stretchable piezoresistive pressure sensor made of polydimethylsiloxane (PDMS)/silver nanowires (AgNWs) composites with microdomes and wrinkled surfaces is developed. The stretchable pressure sensor exhibits high sensitivity that changes negligibly even under uniaxial and biaxial tensile strains of 100% and 50%, respectively. This behavior is attributed to the microdomes responsible for detecting applied pressures being weakly affected by tensile strains, while the isotropic wrinkles between the microdomes deform to effectively reduce the external stress. In addition, because the device comprises all PDMS‐based structures, it exhibits outstanding robustness under repeated mechanical stimuli. The device shows strong potential as a wearable pressure sensor and an artificial crocodile sensing organ, successfully detecting applied pressures in various scenarios. Therefore, the pressure sensor is expected to find applications in electronic skin for prosthetics and human–machine interface systems. Abstract : The omnidirectionally stretchable pressure sensor is developed by mimicking the functional and geometrical properties of the unique sensory organ in crocodile skin. This stretchable pressure sensor can detect pressure changes with high sensitivity even under not only uniaxial tensile strain but also biaxial strain, enabling various practical wearable applications in electronic skin for prosthetics and human–machine interface systems.