Novel fabrication process for a monolithic PMMA torsion mirror and vertical comb actuator

Abstract

This paper presents a novel fabrication process for monolithic PMMA (polymethylmethacrylate) vertical comb-drive actuators utilizing hot embossing, surface-activated direct bonding and elliptical vibration cutting. The robustness and capability of the method are demonstrated through the fabrication of sophisticated PMMA freestanding microstructures, such as a rotation mirror device integrated with vertical comb actuators. The fabrication process consists of silicon mold fabrication by deep-RIE, PMMA microstructure formation by hot embossing, PMMA–PMMA direct bonding by surface activation, releasing or removal of a PMMA layer remaining after hot embossing by elliptical vibration cutting, and finally, metallization by sputtering to form electrodes. An efficient technique to protect the PMMA microstructures during the release process using reinforcement material is applied. A monolithic PMMA torsion mirror driven by a vertical comb actuator has been fabricated successfully.

Anesthetic-, irrigation- and pain-free dentistry? The case for a femtosecond laser enabled intraoral robotic device

“…However, none of the existing MEMS mirrors meet all the requirements for the intraoral high-power laser manipulation, including a low driving voltage of less than 10 volts, a high mechanical reflection angle of over ±10°, a high reflectivity of over 99.99%, a high resonant frequency over 1 kHz, a and small size. Therefore, robust MEMS mirrors need to be developed specifically for this device (46,47). We fabricated successfully micromirrors that satisfied some key parameters, such as small size, and a large deflection angle at low driving voltage (less than 10 volts), as seen in Figure 2.…”

Computation of capacitance and electrostatic forces for the electrostatically driving actuators considering fringe effects

“…In micro-electro-mechanical systems (MEMS) devices, such as switch (Naito et al 2010), variable capacitor (BakriKassem and Mansour 2004), resonator (Elshurafa et al 2011), micro mirror (Amaya et al 2011;Kim et al 2009), gyroscope (Guo et al 2010), microtweezer (Harouche and Shafai 2005) microscanner (Ataman and Urey 2006), interferometer (Lee et al 2011), attenuator (Yeh et al 2006), energy harvester , force sensor (Rajagopalan and Saif 2011), etc., electrostatic capacitors are mostly used components, which are contained of movable mechanical structures for electrostatic actuation or capacitive sensing (Amaya et al 2009;Elata and Leus 2005;Tilleman 2004;Carlen et al 2005;Sun et al 2002;Eswaran and Malarvizhi 2012;Zhang and Fang 2009). Accurate estimation of electrostatic forces or driven voltages on the MEMS structures is very important for efficient design and performance even subsequent use of the electrostatically driving devices (Jaecklin et al 1992;Chen and Miao 2007;Kang et al 2009;Harness and Syms 2000;Beyeler et al 2009).…”

Mechanical properties of polymer/carbon nanotube composite micro-electromechanical systems bridges

“…10,11 Different types of all-polymer MEMS actuators have been demonstrated including polydimethylsiloxane (PDMS) cantilevers, 12,13 SU-8 microgrippers, accelerometers and variable optical attenuators, 14,15 switching arrays based on parylene and polyimide (PI), 16 freely suspended microstructures, and vertical comb actuators based on poly(methylmethacrylate) (PMMA) and polystyrene. 17,18 The conjugated polymer poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a conductive polymer that has high electrical conductivity, simple to processing, non-toxic, biocompatible, and exhibits good thermal and chemical stability. PEDOT:PSS is currently widely used in electronic, optical, electrochemical, and biomedical applications.…”