BioDot PolyDrop™ Syringe Dispensing

A syringe pump operates by first filling the syringe using a fill line connected to a reagent reservoir and then it can switch the outlet connection on the syringe to a second line and reverse the direction of the syringe plunger and displace the fluid through the second line to dispense the reagent using a programmed displacement. The problem is that once the dispensed fluid equals the original fill volume of the syringe the syringe must be refilled by switching the syringe valve to the fill position. At this point the dispensing operation must cease to allow the syringe to refill and then switching back to the dispensing position. In dispensing operations where continuous dispensing such as dispensing on a continuous moving web a single syringe pump will not work. The solution to this problem is to use two syringe pumps for a single dispense operation where the syringes alternately fill and dispense to provide continuous flow for the dispensing operation. This configuration is denoted as a "Tandem Pump". This allows the use of small high resolution syringes in the range of 250 μL to be used. With this configuration continuous dispensing can be achieved with no limitations of the web length.