Light-controlling, flexible and transparent ethanol gas sensor based on ZnO nanoparticles for wearable devices

Abstract

In recent years, owing to the significant applications of health monitoring, wearable electronic devices such as smart watches, smart glass and wearable cameras have been growing rapidly. Gas sensor is an important part of wearable electronic devices for detecting pollutant, toxic, and combustible gases. However, in order to apply to wearable electronic devices, the gas sensor needs flexible, transparent, and working at room temperature, which are not available for traditional gas sensors. Here, we for the first time fabricate a light-controlling, flexible, transparentand working at room-temperature ethanol gas sensor by using commercial ZnO nanoparticles. The fabricated sensor not only exhibits fast and excellent photoresponse, but also shows high sensing response to ethanol under UV irradiation. Meanwhile, its transmittance exceeds 62% in the visible spectral range, and the sensing performance keeps the same even bent it at a curvature angle of 90o. Additionally, using commercial ZnO nanoparticles provides a facile and low-cost route to fabricate wearable electronic devices.

Effect of Au nanoparticle size on the gas-sensing performance of p-CuO nanowires

“…The realization of sensors with excellent sensitivity and selectivity for the detection of toxic gaseous species is essential for minimizing pollution in modern industrialized society [1][2]. The metal-oxide semiconductor is a suitable material system that can detect traces of gaseous species at a concentration in the order of single parts per billion.…”

“…The responses of pristine CuO NWs to CO and NO2 gases are included for comparison. The inset figures in Figs.…”

Nanomaterial‐Enabled Wearable Sensors for Healthcare

“…In a CNT/poly(vinyl alcohol) (PVA) fiber based resistive sensors, high humidity level can swell the filament, decrease the intertube distance of CNTs and thus decrease the resistance of the CNT/PVA fibers. [55] To track the gas concentration for personal wellness and security surveillance, wearable gas sensors based on graphene, [32] rGO, [45,173] ZnO NPs, [174] AgNW-graphene, [175] CNT/SnO 2 NW hybrid film, [31] and polypyrrole NPs [176] were developed to detect the concentration of gases such as nitrogen dioxide (NO 2 ), [31,32,173] ammonia (NH 3 ), [176] hydrogen sulfide (H 2 S), [45] hydrogen (H 2 ), [45] ethanol (C 2 H 5 OH), [45,174] acetic acid (CH 3 COOH), [176] dimethyl methylphosphonate (C 3 H 9 O 3 P, DMMP), [175] acetone (CH 3 COCH 3 ), [175] methanol (CH 3 OH), [175] and tetradecane (C 14 H 30 ). [175] Increase or decrease in resistance is typically detected, depending on whether the gaseous stimulus is an electron donator or an electron acceptor.…”

High Performance CuO Nanorectangles-Based Room Temperature Flexible NH3Sensor

“…For better integration with wearable systems, sensors should be flexible, small in size, and portable. Flexible sensors based on metal oxide (MOx) nanostructures have attracted significant attention considering their high sensitivity, low production cost, ease of fabrication, wear-ability and eco-friendliness [9,10]. There have been several reports on MOx based sensors such as SnO2, ZnO, TiO2, WO3, InO3, CuO, Co3O4 and NiO due to their extremely high sensitivity to hazardous gases (for instance H2S) as well as better selectivity to certain volatile organic compounds (VOCs) [11][12][13][14][15][16][17][18][19].…”

“…The non-significant change in the C0 value suggests the negligible baseline drift with increase in gas concentration. Similarly, the conductance corresponding to recovery curve was also analyzed using desorption model in equation 10. The recovery plots of the flexible CuO sensor for different NH3 concentrations are fitted well and the parameters obtained are also listed in Table II.…”