Category: Automation and High-Throughput Technologies
Variable Drop Volumes in Acoustic Dispensing
Michael Forbush, PhD
Acoustic dispensing is the ideal liquid transfer method for applications requiring between 1nL and 1µL of liquid transfer. Up until this point acoustic dispensing was based on the premise that multiple drops of a fixed volume droplet would be ejected in order to dispense a final total volume. This approach limits the final dispense volume to multiples of the base droplet volume. Using large droplets is a convenient way to decrease the overall dispense times because of the necessity to allow the source liquid surface to settle before the next drop is ejected. Using small droplets on the other hand allows for increased resolution in the final dispense volume. A hybrid approach of using a combination of droplet sizes has been used, but this technique also limits the resolution to the smallest drop size. This work will show the relationships between the fundamental parameters of pressure and application time and how they affect the creation of these acoustic droplets. It will describe the interaction of the parameters used to create different size droplets. It will also show that this fundamental understanding will lead to the ability to dispense final volumes of any volume required.
Michael Forbush– EDC Biosystems - Physicist, EDC Biosystems, Fremont, CA