Suspension Printing And Performance Study On Light-driven Actuators

Microactuators play an important role in the field of Micro Electro Mechanical System(MEMS),which can perform energy conversion and transfer,and cause mechanical deformation of the device.Microactuators are also useful in the field of biomimetic robots or artificial muscles,and have become the research object of scholars in many countries.In this thesis,a light-driven microactuator with a three-dimensional structure is fabricated by the suspension printing technology.The performance of the actuator is studied as well.The actuator is driven in the way of light transmission,which greatly improves the integration of the system compared to the traditional laser irradiation.The photothermal expansion principle of the actuator is studied and a square spiral actuator is designed and simulated.Suspension printing was chosen as the processing scheme,after comparing a variety of micro-nano fabrication technologies.Suspension printing makes up for the limitations of traditional MEMS technology in fabricating three-dimensional structures.The influence of different parameters on printing accuracy is explored.The parameter interval suitable for printing is determined and a good square spiral actuator is successfully printed out.Photothermal conversion material is used for better light absorption.The performance of the actuator is tested using near infrared light with a wavelength of 980 nm.Research on printing parameters shows that: a large inner diameter of the needle will make the printing accuracy worse.Increasing the extrusion rate of the printing material will make the diameter of the printing structure larger.The moving speed of needle has little effect on accuracy within a certain range.The performance study of the square spiral actuator shows that: for a square spiral actuator without photothermal conversion material,the maximum driving distance is only15.9 μm and the highest temperature is 26.1℃,when driving by 0-100 m W lasers.After coating photothermal conversion material,the maximum driving distance is 133.2 μm with 0-90 m W laser powers,which proves the effectiveness of the photothermal conversion material.It has a larger driving distance when compared with the polymer actuator driven by laser irradiation.The temperature variation trend of the actuator is consistent with the simulation result.The highest temperature of the actuator is 46.6℃,which is much lower than the melting point of the material,indicating that the actuator can withstand higher laser power.