This paper presents a novel biosensor structure consisting of a resonator placed at the top wall of a microchannel (Resonator-on-Microchannel: RoM). The proposed biosensor structure is aimed to be used for real-time gravimetric detection of microscale biological targets in liquid environment by tracking the resonance frequency change of the system as the sought particles/cells are attached to the resonator surface. The damping effects are minimized with the help of the proposed resonator placement as well as the hydrophobic coating applied around the resonator gaps. Measurement results show that the quality factor drops only by a factor of 0.5 in liquid environment, validating the operation of the structure. (C) 2016 The Authors. Published by Elsevier Ltd.