LAUSR

Cell orientation is a necessary step in micromanipulation, which significantly affects the outcomes of cell manipulation. Existing cell orientation techniques include the trial-and-error manual approach that suffers from low efficiency, the mechanical contact approaches that have problems of being invasive, and non-contact approaches that are difficult to set up. Objective: This paper proposes a system with a surface-acoustic wave (SAWs) to perform noninvasive cell orientation. Methods: The system employed a SAW chip with a pair of interdigital transducers (IDTs) to rotate embryos around the X and Y axis using acoustic streaming force. Instead of rotating the entire embryos like other methods, the proposed system rotates the cytoplasm alone through the cell chorion. Results: We evaluated the cellular structure recognition algorithm and the rotation control using 100 embryo images and 30 zebrafish embryos. The system successfully recognized all required cellar structures for visual feedback. Furthermore, it rotated all cells into the desired position, including 26 cases completed within 10s with an orientation angle error of less than 4°. All 30 embryos hatched after manipulation. Conclusion: The proposed technique can automatically rotate the cytoplasm through the cell chorion noninvasively. Significance: The system provides a starting point for noninvasive cell manipulation tasks, such as fast intracellular structure scanning and analysis, and microinjection.