AROMA is equipped with syringe pumps that perform the medium transfer tasks in our biosensor. One task of the pumps is to fill and empty the bubbling tank. Before each measurement we need to replace the medium into which the air is bubbled. This is why we need two big pumps. One adds fresh medium while the other one removes the old medium. After the bubbling step we bring the molecule of interest in contact with our engineered E.coli. For this task, a third pump sucks the medium into the microfluidic chip. This pump needs a precise low volume control and the capability to achieve a stop in the flow as quickly as possible. Otherwise the response cannot be read out during this time because E.coli do not rotate if the flow is too high . Syringe pumps are commercial available, but they are very large and very expensive. This is why we looked into building our own customized one.
- Part: The first part is attached directly to the motor via four screws. The rotor - the rotating part of the motor fits through the big hole connecting to the middle shaft. On the sides the two rods are clamped in tightly with the two top screws.
- Part: Similar to the previous part the two rods are clamped in. Additionally we guide the middle shaft with bearings. On top the syringe pump is being clicked in to the mount fitting perfectly. Compared to the original open source model our syringe pump is mounted significantly closer to the middle shaft in order to have less play. This significantly improves the accuracy of the syringe and makes it easier to replace.
- Part: The middle part is the only one out of the three actually moving. It is connected to the center shaft via a nut resulting in a back and forth movement when turning the shaft of the motor. Two linear bearings on both sides enable smooth movement along the two 6mm rods. The end of the syringe pump is connected to this part extruding and intruding it.
|Input||Stopping movement||Time until complete rest|
|Amount in ul||Speed in ul/min||Amount in ul||Speed in ul/min|