Vertical silicon nanowire array-patterned microcantilever resonators for enhanced detection of cigarette smoke aerosols

The fabrication and use of silicon nanowire (SiNW) array-patterned microcantilever sensors for enhancing aerosol mass detection are described. Surface modification of the cantilever is performed selectively by combining the processes of nanoimprint lithography, photolithography and inductively coupled plasma cryogenic reactive ion etching. Cylindrical wire structures of 300 nm diameter with aspect ratios of 3-7 can be realised for the current SiNWs, which can be altered depending on the nanoimprint stamp size and etching recipe. Owing to the rise in the collection surface area of the sensor provided by vertical SiNWs, an increase of aerosol sampling efficiency can be obtained during cigarette smoke exposure, which is a factor of 1.5 higher than that of a corresponding plain cantilever. This proposed structure is intended to be used as a sensor module of a personal aerosol mass detector.