An embedded microchannel in a MEMS plate resonator for ultrasensitive mass sensing in liquid

Abstract

A mass sensor innovative concept is presented here, based on a hollow plate Micro Electro Mechanical System (MEMS) resonator. This approach consists in running a solution through an embedded microchannel, while the plate resonator is actuated according to a Lamé-mode by electrostatic coupling in dry environment. The experimental results have shown a clear relationship between the measured shift of the resonance frequency and the sample solution density. Additionally, depending on the channel design and the solution properties, the quality factor (Q-factor) was noticed maintaining its level and even substantial improvement in particular cases. Resonators demonstrate resonance frequencies close to 78 MHz and Q-factor of a few thousands for liquid phase detection operating at ambient temperature and atmospheric pressure. Frequency fluctuations study revealed a 13 Hz instability level, equivalent to 1.5 fg in mass. Using a fully electronic readout configuration, a mass responsivity of ca. 850 fg kHz(-1) was monitored.

Hollow Lamé mode MEMS mass sensors with 10 ppb-range stability for particles counting and weighing in fluid

“…Sensors C and D both exhibited 140-kHz frequency shifts between air and water, and -factors of the same order than in air (Figure 9), as was observed on a previous generation of Lamé mode chips [9]. The Allan deviation is similar for averaging times below 200 ms, which are the values most consistent given the traveling time of a particle inside the channel (a few 10 ms).…”

High-frequency nano-optomechanical disk resonators in liquids

“…To circumvent these problems novel structures and techniques have been developed. An efficient approach is to use vibrating microchannel cantilevers where the liquid flows directly inside the resonator in order to reduce the induced dissipation [10][11][12] . Fibered microcapillaries 13 adopt this approach too with a more integrated optical detection.…”

Extracellular Vesicles: Isolation Methods

“…While most devices use cantilever-type resonators, variants based on oscillating plates exist and operate without vacuum packaging to reduce the complexity of manufacturing. [77,78] When the device is miniaturized down to the microscale (Figure 6b), particles as small as 30 nm i.e., on the attogram scale, can be weighted. [79] This method has revealed clear differences in heterogeneity of the exosomes' buoyant mass distribution according to their cellular origin through a nanoscale version of this technique, by weighting exosomes secreted from fibroblasts and hepatocytes (Figure 6c).…”