A stretchable, room-temperature operable, chemiresistive gas sensor using nanohybrids of reduced graphene oxide and zinc oxide nanorods

Chemiresistive gas sensors with high-performance, stretchability, and low power consumption are of great interest to developers of wearable applications but sensing materials compatible with mechanical deformability and operability that do not require thermal heating have proven hard to find. Here, a high-performance and stretchable chemiresistive gas sensor based on nanohybrids of reduced graphene oxide (rGO) and vertically grown zinc oxide (ZnO) nanorods (NRs) on a stress-absorbable, elastic, three-dimensional (3D) micropatterned polydimethylsiloxane (PDMS) substrate is described for ultra-sensitive gas sensing at room temperature. The ZnO NRs grown on an rGO network combined with a stretchable substrate produced mechanical stretchability up to a tensile strain of 20 %, ultra-high-sensitive detectability as low as 40 ppb of NO₂ due to the presence of a large sensing area, and high selectivity of NO₂ to other gases, including SO₂, while the rGO eliminated the need for thermal heating. In addition, the nanohybrid sensor exhibited rapid response and recovery times and superior reproducibility compared with an rGO sensor.