An investigation of vibration-induced protein desorption mechanism using a micromachined membrane and PZT plate

A micromachined vibrating membrane is used to remove adsorbed proteins on a surface. A lead zirconate titanate (PZT) composite (3 × 1 × 0.5 mm) is attached to a silicon membrane (2,000 × 500 × 3 μm) and vibrates in a flexural plate wave (FPW) mode with wavelength of 4,000/3 μm at a resonant frequency of 308 kHz. The surface charge on the membrane and fluid shear stress contribute in minimizing the protein adsorption on the SiO 2 surface. In vitro characterization shows that 57 ± 10% of the adsorbed bovine serum albumin (BSA), 47 ± 13% of the immunoglobulin G (IgG), and 55.3~59.2 ± 8% of the proteins from blood plasma are effectively removed from the vibrating surface. A simulation study of the vibration-frequency spectrum and vibrating amplitude distribution matches well with the experimental data. Potentially, a microelectromechanical system (MEMS)-based vibrating membrane could be the tool to minimize biofouling of in vivo MEMS devices.