## 4 Experimental Results  
The experimental characterization of the test device was focused on the pump efficiency of the fluid transfer, in addition to other factors, such as the properties of the fluid, the temperature, the design and the speed selected. The purpose of the pump is to move the liquid to different height levels from the tank and the pump in a certain amount of time. The measured parameters during the conducted tests are the temperature, the speed and the volume of fluid to transport that determine the flow rate of the pump. The volume of the fluid expressed in mL was pumped in one minute and measured using a graduated cylinder. The operating temperature was recorded at the same time during the measurement tests. The test was carried out to pump the fluid with a difference in height between the tank and the pump. The height difference was 0.5 m, according to the design of the device. The height difference between the pump and the highest point of the tank is 1 mm for a volume of liquid pumped of 1 mL. The pumping speed is set from 10 to 100 % with 10-point series of measurements conducted maintaining the same operation conditions associated with a constant ambient temperature of 23 \({}^{\circ}\)C. The baseline of 10 % equal to 10 s corresponds for sucking in and extruding the liquid in the pump in which the diaphragm makes a full movement. Meanwhile, 100% corresponds to 1 s for a full cycle of operation. For this reason, an interval of time sufficiently long was maintained during the measurements in order ensure the low temperature of the electromagnets. The accuracy of the measurements, the volume of pumped liquid and the temperature were defined as \(\Delta ml=1\) and \(\Delta T=0.5\)\({}^{\circ}\)C, respectively.  
Figure 7 shows the temperature expressed in \({}^{\circ}\)C and the volume of liquid in mL as a function of pump speed in %. As the specific speed of the pump increases, the specific speed  
Figure 6: (**a**) Side view of display and realized pump; (**b**) top view of diaphragm pump and container for measurement of liquid volume; (**c**) Side view of diaphragm pump.  
increases and, consequently, the efficiency and performance should increase. In the case of the realized pump, a decrease in the pumped fluid is observed when the pump speed is increased. This is due to the increase in the drag forces that act in the direction opposite to the motion of the pumped fluid with higher viscosity, resulting from an insufficiently long diaphragm stroke time. The full movement range of the diaphragm needs a short amount of time to return to the initial position of the membrane, and high resistance forces are generated by the liquid suction process, and the power of the device is too low. Therefore, an increase in temperature was noted for the increase in pump speed during the testing device. This is due to the increase in the number of switch overs associated with the accelerated duty cycle. The higher number of switches causes an increase in the temperature of the electromagnets. In addition, the increased temperature of the electromagnet reduces its resistance, providing the current changes. The result of this phenomenon can conduct the reduction of pump power performance, because during testing, the parameters of the voltage source were unchanged and susceptible to destabilization due to changes in the resistance of the electromagnet system. The solution may be to control the device from a current source to provide better current performance and constant pump power. In fact, the measurement results exhibit a linearity of the pumped liquid that can be regulated and controlled by the switching speed of the electromagnet's polarization.  
In the future, the heat dissipation and cooling system can be improved and the increase in the stroke time in each speed mode can be as well.