On-chip integrated multiple microelectromechanical resonators to enable the local heating, mixing and viscosity sensing for chemical reactions in a droplet

•Single chip microsystem integrating MEMS actuators and sensors to perform microscale chemical reactions.•Efficient heating and mixing of a droplet was achieved using MEMS actuator.•On-line viscosity monitoring in a droplet was realized using MEMS sensor.•Diels-Alder reaction in a single droplet was performed using the integrated microsystem.

On-chip integrating several functional components for developing integrated lab-on-a-chip microsystem remains as a challenge. In this work, by employing multiple microelectromechanical resonators both as actuators and sensors, on-chip heating, mixing and chemical reaction monitoring are successfully demonstrated. Mechanism studies using COMSOL simulations indicate that the local heating and mixing are induced by the acoustic wave attenuation during its transmission in liquid. On-line chemical reaction monitoring is realized by viscosity sensing using the same resonator through impedance analysis. Classic Diels-Alder reaction in a single droplet was performed to verify the feasibility of using such microsystem for mixing, heating and online reaction monitoring at microscale.