SonoRotor: An Acoustic Rotational Robotic Platform for Zebrafish Embryos and Larvae

Rotation manipulation is an essential component of biological microscopy and can become integral to multidisciplinary research and applications. On-chip rotation of microobjects with spherical shapes like biological cells and model organisms has been demonstrated based on advanced microfluidic techniques. To date, however, biocompatible, easy-to-fabricate, easy-to-operate, and controlled rotation of small animal models with slender bodies remains a challenge. Here, we present SonoRotor, a miniaturized acoustic rotation platform for animal models using a single elongated acoustically activated air bubble. In the presence of an acoustic field, the trapped elongated air bubble oscillates and induces a polarized vortex in the surrounding liquid. Zebrafish embryos (spherical) and larvae (slender), typically larger than hundreds of micrometers, become trapped near the oscillating bubble and undergo a controllable, high-speed, and stable out-of-plane rotation. By controlling the voltage applied to our device, we can adjust the rotation speed of the zebrafish. The developed acoustic rotation manipulation platform is simple, cost-effective, allows multiview imaging, high-throughput operation, and can be combined with downstream analytical techniques to perform a variety of biological micromanipulation on small animal models.