Acoustofluidic Particle Trapping in a Structured Microchannel Using Lateral Transducer Modes
Sprache des Titels:
Englisch
Original Kurzfassung:
By using lateral extensional modes of piezoelectric plate transducers for the actuation of a microfluidic chip containing a structured microchannel, we achieved two-dimensional single-node acoustofluidic particle trapping inside a circular cavity as well as two-dimensional multi-node trapping in straight channels. In order to manipulate the particles in two lateral dimensions, we used two separate PZT transducers attached to the bottom of the microfluidic chip, where each is responsible for generating a standing acoustic wave in a specific direction inside the microfluidic structures of the chip. We demonstrate trapping of polymer microspheres and trapping of human embryonic kidney cells with a performance that can compete with current bulk acoustic methods which typically employ transducer thickness modes. The acoustic energy density of the involved acoustic fields reaches several hundred (430) Joules per cubic meter, leading to trapping times of tenths of a second (150 ms) and nanonewton trapping forces (0.42-1.7 nN). The relatively low, sub-megahertz resonance frequency of the utilized lateral transducer mode in the cavity trapping, results in a large, millimeter long wavelength of the acoustic wave inside the fluid, which enables collection of comparably large volumina of multiple tens of nanoliter containing several thousands of particles or cells. Consequently, with the large volumes involved, it appears feasible to trap bigger objects, like multicellular organisms or organoids with approximately one millimeter in size.
Forschungs-