Abstract

Living systems can respond to external stimuli by dynamic interface changes. Moreover, natural wrinkle structures allow the surface to switch dynamically and reversibly from flat to rough in response to specific stimuli. Artificial wrinkle structures have been developed for applications such as optical devices, mechanical sensors, and microfluidic devices. However, chemical molecule‐triggered flexible sensors based on dynamic surface wrinkling have not been demonstrated. Inspired by human skin wrinkling, herein, a volatile organic compound (VOC)‐responsive flexible sensor with a switchable dual‐signal response (transparency and resistance) is achieved based on a multilayered Ag nanowire (AgNW)/SiOx/polydimethylsiloxane (PDMS) film. Wrinkle structures can form dynamically in response to VOC vapors (such as ethanol, toluene, acetone, formaldehyde, and methanol) due to the instability of the multilayer induced by their different swelling capabilities. By controlling the modulus of PDMS and the thickness of the SiOx layer, tunable sensitivities in resistance and transparency of the device are achieved. Additionally, the proximity mechanism of the solubility parameter is proposed, which explains the high selectivity of the device toward ethanol vapor compared with that of other VOCs well. This stimuli‐responsive sensor exhibits the dynamic visual feedback and the quantitative electrical signal, which provide a novel approach for developing smart flexible electronics. A dual‐signal responsive flexible volatile organic compound (VOCs) sensor is proposed based on surface wrinkles with both dynamic visual feedback and a quantitative electrical signal. Tunable sensitivity and selectivity can be well controlled, and the high selectivity toward ethanol vapor is explained by a proximity mechanism. This platform can provide a novel approach for developing smart flexible electronics.

Full article:https://www.researchgate.net/publication/332042793_Bioinspired_Flexible_Volatile_Organic_Compounds_Sensor_Based_on_Dynamic_Surface_Wrinkling_with_Dual-Signal_Response