  Optoelectronic tweezer-driven microrobots (OETdMs) are a versatile
micromanipulation technology based on the use of light induced
dielectrophoresis to move small dielectric structures (microrobots) across a
photoconductive substrate. The microrobots in turn can be used to exert forces
on secondary objects and carry out a wide range of micromanipulation
operations, including collecting, transporting and depositing microscopic
cargos. In contrast to alternative (direct) micromanipulation techniques,
OETdMs are relatively gentle, making them particularly well suited to
interacting with sensitive objects such as biological cells. However, at
present such systems are used exclusively under manual control by a human
operator. This limits the capacity for simultaneous control of multiple
microrobots, reducing both experimental throughput and the possibility of
cooperative multi-robot operations. In this article, we describe an approach to
automated targeting and path planning to enable open-loop control of multiple
microrobots. We demonstrate the performance of the method in practice, using
microrobots to simultaneously collect, transport and deposit silica
microspheres. Using computational simulations based on real microscopic image
data, we investigate the capacity of microrobots to collect target cells from
within a dissociated tissue culture. Our results indicate the feasibility of
using OETdMs to autonomously carry out micromanipulation tasks within complex,
unstructured environments.
