Abstract
We report a high-quality-factor (Q) film bulk acoustic resonator (FBAR) operating in liquid environments. By integrating a microfluidic channel to a longitudinal-mode FBAR, a Q of up to 150 is achieved with direct liquid contacting. A transmission line model is used to theoretically predict the Q behavior of the FBAR. The model suggests an oscillatory pattern of Q as a function of the channel thickness and the acoustic wavelength in the liquid, which is experimentally verified by precisely controlling the channel thickness. This FBAR biosensor is characterized in liquids for the real-time in situ monitoring of the competitive adsorption/exchange of proteins, the Vroman effect. The FBAR offers a minimum detectable mass of 1.35 ng2 and is successfully implemented in a Pierce oscillator as a portable sensing module.
Original language | English (US) |
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Article number | 5668490 |
Pages (from-to) | 213-220 |
Number of pages | 8 |
Journal | Journal of Microelectromechanical Systems |
Volume | 20 |
Issue number | 1 |
DOIs | |
State | Published - Feb 2011 |
Keywords
- Acoustic resonators
- Q factor
- biomedical transducers
- piezoelectric resonators
ASJC Scopus subject areas
- Mechanical Engineering
- Electrical and Electronic Engineering