Design and evaluation of a micro resonator structure as a biosensor for droplet analysis with a standard fabrication method

Abstract

Purpose

In this work, the sensing and actuating elements are designed with interdigitated capacitors away from the sensitive element on which the droplet is placed. This pattern helps to prevent interference of electrical elements with the droplet. Choosing shear resonance mode at this proposed structure minimizes the damping effect of droplet touch by the resonator structure. The glass-based standard fabrication method of the proposed biosensor is presented exactly.

Design/methodology/approach

Mechanical resonator sensors are extremely limited because of the high damping factor and the high electrical conductivity in the aqueous environment. In this work, a molecule detector biosensor is proposed for droplet analysis, which is possible to fabricate using micro-electro-mechanical systems (MEMS) technology. By electromechanical coupling of resonators as a mechanical resonator structure, a standing mechanical wave is formed at this structure by electrostatic actuating elements.

Findings

In this paper, a mechanical resonator structure as a biosensor is proposed for micro-droplet analysis that can be fabricated by MEMS technology. It is designed at a lower cost fabrication method using electrostatic technology and interdigitated capacitors. The response of the biosensor displacement frequency at the resonance frequency of the desired mode is reasonable for measuring the capacitive changes of its output. The mass sensitivity of the proposed biosensor is in the range of 1 ng, and it has a large sensitive area for capturing target molecules.

Originality/value

To evaluate the quality of the proposed design, the stimulated analysis is conducted by COMSOL and results are presented.

Citation

Eidi, A., Shamsi, M. and Badri Ghavifekr, H. (2022), "Design and evaluation of a micro resonator structure as a biosensor for droplet analysis with a standard fabrication method", Sensor Review, Vol. 42 No. 2, pp. 263-273. https://doi.org/10.1108/SR-07-2021-0209