Graphene nanowall nanomesh boosts wearable gas sensor sensitivity sixfold

Researchers at the Daegu Gyeongbuk Institute of Science and Technology (DGIST), Hanbat National University, Chungnam National University, the Korea Institute of Industrial Technology, Kyungpook National University, and the Gumi Electronics and Information Technology Research Institute (GERI) have developed a hierarchical graphene nanowall (GNW) “nanomesh” that delivers up to six times the sensitivity of conventional planar graphene gas sensors, while remaining flexible and breathable enough for wearable use.

Wearable gas sensors need to operate sensitively at room temperature while staying mechanically compliant for long-term wear, but most existing designs rely on planar sensing layers that limit accessible surface area. Vertically oriented graphene nanowalls offer an edge-rich, high-surface-area alternative, but growing them conventionally requires temperatures above 600°C, incompatible with flexible polymer substrates — and transfer-based workarounds keep the resulting structure planar rather than truly three-dimensional. The team’s solution was a “3D-on-3D” architecture: graphene nanowalls grown directly onto a three-dimensional polymer nanofiber nanomesh rather than a flat film. An electrospun polyamic acid nanomesh was converted to polyimide, coated with a thermally robust parylene layer, and given a thin SiO2 nucleation layer, allowing vertically oriented GNWs to be grown across the fiber network via low-temperature plasma-enhanced chemical vapor deposition without collapsing the underlying scaffold.

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