Nanoscale Thermal Management of Single SnO₂ Nanowire: Pico-Joule Energy Consumed Molecule Sensor

Here we report the thermal management of oxide nanowire sensor in both spatial and time domains by utilizing unique thermal properties of nanowires, which are (1) the reduced thermal conductivity and (2) the short thermal relaxation time down to several microseconds. Our method utilizes a pulsed self-Joule-heating of suspended SnO₂ nanowire device, which enables not only the gigantic reduction of energy consumption down to ∼10² pJ/s, but also enhancement of the sensitivity for electrical sensing of NO₂ (100 ppb). Furthermore, we demonstrate the applicability of the present method as sensors on flexible PEN substrate. Thus, this proposed thermal management concept of nanowires in both spatial and time domains offers a strategy for exploring novel functionalities of nanowire-based devices.