Fabrication and characterization of DRIE-micromachined electrostatic microactuators for hard disk drives

Abstract

In this paper, deep micromachined threedimensional (3-D) electrostatic microactuators used for dual-stage positioning system of hard disk drives are reported. Actuators with parallel-arranged comb drives enhance the electrostatic driving force. By using proper flexures, secondary stage actuators will drive the magnetic head with fast response and high accuracy. Fabrication of the actuators starts with a 200-lmthick n-type silicon wafer, and it is subsequently bonded to a Pyrex glass substrate, which can be called silicon-on-glass process. This process is more costeffective than the SOI wafer process, and the high aspect ratio structures with large thickness also provide good strength and reliability for the microactuators. Deep RIE and wafer bonding techniques were utilized to fabricate the electrostatic actuators. The fabricated actuators were statically and dynamically characterized for three different designs of straight-flexures, foldedflexures and quad-flexures with bandwidth of 7.15, 5.85 and 15.85 kHz, respectively. With proper designed flexures, the proposed microactuators would fulfill the requirements of the dual-stage servo of hard disk drives.

Effects of surfactant and nanofluid on the performance and optimization of a microchannel heat sink

“…While width ratio, β, limits the minimum of channel width, w w , to 5 µm according to flexure width done by Chan et al (2006). Current micromachining and etching limitation do surpass 5 µm but it is prone to defect such as scalloping and researches were mostly focused on microchannel or trench dimension rather than its wall (Kiihamäki & Franssila, 1999;Chan et al, 2006;Chen et al, 2007;Lindroos et al (2010); Lips & Puers, 2016;Tang et al, 2018). The lower and upper limits of the design variables are the maximum and minimum size for channel width, w c , and wall width, w w , for the microchannels with a constant channel height, H c. Utilizing MOPSO optimization, aspect ratio, α, and width ratio, β, adhere to the main equation of particle swarm as follows,…”

Friction characteristics of the curved sidewall surfaces of a rotary MEMS device in oscillating motion

“…The friction-testing device was fabricated based on a siliconon-glass (SOG) micromachining process [18]. The wafers for the silicon devices were 150 μm thick N-type (1 0 0) single-crystal wafers with a resistivity of 0.1-1 cm, and [1 1 0] surfaces were used at the center of the contact sidewall interface.…”

Experimental verification of an out-of-plane repulsive-force electrostatic actuator using a macroscopic mechanism

“…Among the four major actuation technologies used in MEMS devicents, i.e., electrostatic actuation (Aksyuk et al 2003;Chen et al 2007;Hagelin and Solgaard 1999;Lee et al 1999;Van Kessel et al 1998), electromagnetic actuation (Bernstein et al 2004;Debray et al 2004), thermal actuation (Jain et al 2004) and piezoelectric actuation (Goto 1998;Xu et al 2006), electrostatic actuation is adopted in many applications due to its high compatibility with micro fabrication technology, low power consumption and quick response. Conventional micro electrostatic actuators use the attractive force between two parallel electrodes to generate movement, i.e., the two electrodes move towards each other.…”