| dc.description.abstract | Microactuators are the source of driving force in MEMS, and are generally classified into four types: thermoelectric actuators, piezoelectric actuators, electrostatic actuators, and electromagnetic actuators. The thermoelectric actuator uses a heating medium (such as liquid or air) to change the volume of the medium to generate a driving force. In this experiment, a heater with a diameter of 120 μm is used to fabricate a heater and combined with a polymer material (PDMS) to form a Bimorph thermal actuators structure, which use different coefficient of thermal expansion to cause different volume changes of the two materials by inputting voltage and current, causing the large end of the coefficient of thermal expansion to bend toward the small end of the coefficient of thermal expansion, and measuring the deformation and bending Angle, and then evaluate the feasibility of such microactuators in application.
The process of this paper firstly uses the Bimorph-shaped variable formula to analyze, designing a tiny thermal actuator and capable of generating an actuation effect in a narrow area to achieve large displacement and low output power. Several low Young′s modulus of material are analyzed in the process.The appropriate material and the size of the material capable of generating large plane displacement, and a series of experiments to control the temperature and analyze the thickness of the PDMS that can properly control the input power, and then make The heater mold is combined with PDMS and copper wire heater to form a bimorph cantilever beam thermal actuator. The thermal actuator can be measured to control its deformation and bending angle, then compare with theoretical analysis results .
The results show that the larger the thickness of PDMS, that the deformation and the bending angle increase. The theoretical formula analysis can produce a deformation (1.79mm) at PDMS thickness of 631μm and a heating temperature of 150°C, while the temperature increase will lead to a decrease in the deformation, and the experimental result shows that the deformation of the PDMS thickness of 631 mm is 1.438 mm, which is 0.35 mm from the theoretical value. The reason is speculated that the heater curing PDMS is uneven and the experimental error is caused.
The experiment finally raises the temperature to 160 ° C and the heater will burn out. Therefore, it is estimated that the heating limit of this group of actuators is here, and the process will be adjusted in the future to reduce the experimental error and increase the shape variable. | en_US |