A Piezoelectric Flexural Plate Wave (FPW) Bio-MEMS Sensor with Improved Molecular Mass Detection for Point-of-Care Diagnostics

Abstract

A piezoelectric FPW-sensor has been developed for a point of care device in this work. The Bio- MEMS FPW-sensor consists of an electrode configuration termed as an interdigital transducer (IDT) placed on a membrane. An input IDT excites and an output IDT detects the propagating acoustic waves through a PZT layer. Design optimizations and fabrication improvements of the FPW-sensor led to significantly reduced attenuation of the wave signal and the damping of the propagating waves between the IDTs. The working principle of mass loading is shown using different low-viscous liquids. A densitydependent sensitivity of -0.39 MHz/g/cm³ was evaluated. After the membrane was functionalized, the Bio-MEMS FPW-sensor was used to measure a specific chemokine in complex solution. By design improvements, the resolution was significantly increased from 0.7 Hz/nM to 14 Hz/nM.

Cell Alignment in Aqueous Solution Employing a Flexural Plate Wave Piezoelectric MEMS Transducer

“…Specifically, in a standing wave field the acoustic radiation force (ARF) drives the particles dispersed in liquid into acoustic pressure nodes, thus allowing their manipulation and alignment [17,18]. Bulk acoustic waves (BAW) [19], surface acoustic waves (SAW) [20], and flexural plate waves (FPW) [21], are typical acoustic modes exploited in piezoelectric transducers. The adoption of FPWs has the advantage of exhibiting a wave velocity that decreases with decreasing plate thickness and may become lower than the wave velocity in liquids.…”

Electrostatic Micro-Electro-Mechanical-Systems (MEMS) Devices: A Comparison Among Numerical Techniques for Recovering the Membrane Profile

“…Combining among them micro-size mechanical and electronic devices, MEMS technology, emerged in the second half of the 1960s [3], is now considered as one of the most promising technologies of the 21th century [4], [5]. The industrial usages of MEMS are incredibly varied, ranging from surgicaldiagnostic-therapeutic microsystem [6], bio-sensors [7], and tissue engineering [8] to wireless and mobile applications [9]. Furthermore, MEMS are considered extremely interesting for mechatronics applications, because of their small size as well as the easy of realization with relatively low costs [10].…”