Thin-film silicon MEMS DNA sensors

Abstract Thin-film microelectromechanical molecular sensors are fabricated at temperatures below 110 °C on glass substrates. The microelectromechanical structure consists of a surface micromachined bilayer bridge of phosphorous-doped hydrogenated amorphous silicon and aluminum. There is specific binding of DNA to hydroxylated bridge surfaces through silanization chemistry. Microbridges are electrostatically actuated and the resonance frequency measurements are performed in vacuum in the initial state after fabrication, after surface functionalization and after DNA immobilization. The sensor is able to detect the functionalization molecular layer and the DNA molecules attached to the surface through a shift in its resonance frequency.