Developing Optopiezoelectric Materials for Distributed Sensors and Piezoelectric Actuators

• Main Authors: Wenchi Chang, 張雯琪
• Other Authors: Chih-Kung Lee
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/79209426053907679217

博士 === 國立臺灣大學 === 應用力學研究所 === 103 === The micro-/ nano mechanical manipulation has been recently progressively developed for micromechanical equipment, biochips, and microfluidic devices. Since the end of the 19th century, the atomic force microscopy, optical tweezers, and magnetic tweezers have been proposed to control single cell or atom. Some indirect control methods, such as optothermal mechanism, opto-electrowetting (OEW) and optical dielectrophoresis (ODEP) techniques, provide us with larger force, better efficiency, and less damage on the objects. In these years, many optical sensitive composite materials are integrated into control systems; the electrical or thermal field can be modulated by light pattern for manipulating particles or droplets. However, these conventional optical control techniques deliver actuating or sensing force only in the nN range. In this dissertation, the optopiezoelectric actuator or sensor can modulate mN force by varying the distribution of the illuminated light pattern. In Chapter 3, a PZT actuator is triggered with 175 DC voltage in microfluidic device to efficiently trap living C. elegans. In Chapter 4, the optopiezoelectric cantilever beam actuator of spiropyran/ liquid crystal- PZT performs UV (365 nm, 0.7 mW/cm^2) modulated amplitude with few tens (Hz) frequency shift. And the P(VDF-TrFE)/ TiOPc optopiezoelectric sensors are fabricated and developed with an optimal 10 % w.t. TiOPc concentration. In traditional point bending sensor, the signal error is closely related to its position. Thus in Chapter 5, a full field optopiezoelectric bending sensor, PZT- 40% w.t. TiOPc/ resin, performs less than 10% error with numerical analysis. Without effects on the host structure, it has fast and easy modulation capability by using spatially distributed light illumination patterns. Overall, this thesis discusses the piezoelectric effect in microfluidics, developing and understanding the optopiezoelectric performance. We expect the simulation, experimental and analytical results can provide some evidences and references for future innovative optopiezoelectric or optopiezoelectric fluidics application.