Tom Baden, from the University of Sussex, has generously shared the following device with Open Behavior:
Designed for ease of use, robustness and low-cost, the “Openspritzer” is an open hardware “Picospritzer” as routinely used in labs around the world for administering picoliters of liquid to biological samples. The performance of Openspritzer and commercial alternatives is effectively indistinguishable.
The system is based on a solenoid valve connected to a pressure gauge. Control can be attained directly via an external TTL pulse or internally through an Arduino set by a rotary encoder. The basic setup can be put together for 3-400€, or substantially less if you are prepare to shop around.
Check out projects similar to this!