The overall goal of this experiment is to fabricate a conduction micropump using symmetric planar electrodes on flame-retardant, glass-reinforced expoxy copper-clad laminate in order to test the influence of chamber dimensions on the performance of a conduction micropump. The main advantage of this technique is the voltage involved is a low several hundred volts. And the fabrication cost is relatively low.
Though this method can provide insight into the mechanism of the conduction pump, it can also be applied to many other systems such as trunk delivering systems and micro-cooling systems. To begin, place the plate inside the beaker with the electrode surface facing down to help remove small particles like dust from the plate surface. Also, place the holder, the inlet and outlet tubes and other tools used in the experiments inside the beaker.
Then pour enough 99.5 per cent acetone to immerse the items. Place the beaker inside the ultrasonic washer, and turn it on for five minutes. Next insert the inlet and outlet stainless steel tubes into the two holes on the cover plate.
Place a chamber plate made of silicone membrane on the electrode plate, and then cover it with a cover plate. Stack and align the cover plate, the chamber plate and the electrode plate from top to bottom and insert the aligned plates into the holder. Use an M2 bolt to fix the plates inside the holder.
Press the plates together by tightening the bolts. Next use two polyurethane hoses with external diameters of four millimeters and internal diameters of two millimeters to connect the inlet and outlet stainless steel tubes. Connect an amperemeter, a 500 volt DC power source and the micropump in series.
Then insert a one milliampere fuse between the amperemeter and the power source to protect the amperemeter in case the micropump is shorted. Finally insert the inlet hose into a 50 milliliter beaker with 20 to 30 milliliters of acetone inside. To prepare for the experiment, use a cylinder to extract acetone to fill up the micropump.
After the liquid level reaches the outlet hose, continue to extract ten milliliters of acetone inside until all bubbles are pushed away from the chamber. Repeatedly aspirate the acetone out of the pump and then re-inject it without bringing any air inside the pump to help remove bubbles. To perform the static pressure test, attach the outlet hose to a small frame so that the hose can remain straight and vertical.
Put a ruler alongside the outlet hose to measure the liquid level. Connect the micropump to the power source. Start the test by raising the voltage to 500 volts and then mark down the initial liquid level.
After the liquid level becomes stable, record the time, the final liquid level and the electric current. Continue to record the liquid level and the current every ten seconds until the micropump breaks down. To perform the flow rate test, use a large measuring cylinder to collect the liquid coming out of the outlet hose.
Be sure to fix the outlet hose so that the end remains at the same altitude as the liquid level in the beaker. Switch on the power source. Start the test by raising the voltage to 500 volts and then mark down the initial liquid level.
As the liquid starts to flow out of the outlet hose, record the volume of acetone inside the measuring cylinder every ten seconds. As the experiment goes on, add acetone to the beaker to maintain the liquid level. Shown here is the increasing rate of pump pressure with an increase in voltage.
When the voltage reaches 500 volts, the pump pressure reaches 1, 100 Pascal. The pump static pressure rises with the pump chamber height. The pump performance reaches its highest point when the chamber height is 0.2 millimeters.
Then the static pressure drops when the chamber height continues to increase. Based on these results, 0.2 millimeters is considered the best value for the chamber height. By increasing the chamber length, the static pressure rises, with a big slope until a chamber length of 23 millimeters.
Then it continues to rise with a smaller slope, indicating a gradual rise. There is a slight decrease in the static pressure versus chamber width curve when the chamber width increases from two millimeters to three millimeters. Afterwards, the static pressure remains at a certain level as the chamber width increases.
Once mastered, this technique can be done in half an hour if it is performed properly. After watching this video, you should have a good understanding of how to set up a platform and test the performance of a conduction micropump. Don't forget that working with acetone can be hazardous and precautions such as wearing rubber gloves should always be taken while performing this procedure.
We showed demonstration of this method is critical. A short circuit may occur during the experiment if the washing and inspecting steps are not conducted carefully.
