Capillary Pressure Control System for Teleoperated and Automatic Biomanipulations

This paper presents the design and development of a novel capillary pressure control system aimed at improving biomanipulations by overcoming limitations of current commercial microinjector devices, namely unilateral pressure ranges and the lack of remote controllability. The system presented here is able to actively and precisely control both positive and negative pressures, and is fully computer controlled, supporting both teleoperated and automatic operations through a high-speed communications link. In addition, it offers two control modes: the automatic pressure control mode with resolution down to 0.008 PSI; and an automatic volume control mode with resolution of 0.2μl. Experiments demonstrating the final system specifications are described, including step responses and measurements of maximum pressure control errors. The controllable pressure range achieved covers values from -7.25 to +12.75 PSI, within which the system is capable of outputting pressure pulses with a minimum period of 3ms. The achieved specifications provide confidence the system is appropriate for delicate biomanipulations such as blastocyst and neuron microinjections, and that it will enable the creation of superior automatic microinjection controllers.