Description
Manipulation of biological cells is a particularly important process for understanding cell properties, disease diagnosis, and laboratory testing. Previously, our lab has completed work in cancer stem cell (CSC) isolation using a microfluidic mixing device known as a herringbone (HB) chip. To improve the cell capture efficiency, the addition of an acoustic wave can be introduced to separate cells with different compressibility and density. Acoustic waves allow for free flow manipulation of a media containing a variety of cells with different sizes and physical characteristics. One-dimensional standing surface acoustic wave (SSAW) can be generated by using two parallel interdigital transducers (IDTs) on a 4 Inch 128° Y-Cut surface acoustic wave (SAW) grade LiNO2 wafer due to the piezoelectric material properties of the wafer. IDT design allows for a given wavelength of the SSAW to be generated between the two IDTs. Our design proposes a 40 μm finger width with a 80 μm spacing between electrodes. To create a SSAW within to the length of the microchannel of the microfluidic chip, the aperture of the wave will be 15 mm. The IDTs coupled with an AC signal at a frequency of 16.5 MHz, supplied from a function generator creates the SSAW in the region between the two IDTs. The microfluidic chip is positioned between the two IDTs to have the SSAW pressure nodes located in the center of the micro channels. The acoustic force applied to the particles move laterally to different regions of the channel based on particles physical characteristics. Thus, the manufacturability of this device provides possibility of increased cell capture in the cell separation microfluidic device.
