• 대한기계학회논문집A
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• 제20권5호
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• pp.1363-1371
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• 1996

This paper presents the design, fabrication, and testing of polysilicon electrostatic microactuators that resonate in the direction parallel to the silicon susbstrates. A set of six different designs has been developed using a theoretical model and design formulae developed for the mocroactuators. Microactuator prototypes are fabricated from a 2.1 $\mu{m}$-thick LPCVD polysilicon film, using a 4-mask surface-micromachining process. The prototypes are tested under a d.c. bias voltage of 45V with an a.c. drive voltage amplitude of 20 v.Measured resorant frequencies are in the ranges of 40-60 kHz, showing a good agreement to their theoretical estimates within error bounds of .$\pm$.5%. Important issues inthe design and microfabrication of the microactuators are discussed, together with potential applicaitons of the key technology involved.

• 대한전자공학회논문지SD
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• 제38권9호
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• pp.605-610
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• 2001

본 연구에서는 저전압 구동형 정전방식을 이용하여 마이크론 이하 간격(sub-micron gap)을 갖는 마이크로액추에이터를 제작하였다. 사각 팁과 삼각 팁의 두 가지 방식으로 마이크로액추에이터를 제작하여 비교하였다. 삼각 팁으로 제작된 마이크로액추에이터의 gap은 0.55㎛∼l.35㎛었다. 0.55㎛ gap을 갖는 제작된 마이크로액추에이터의 경우에 13V의 낮은 전압에서 1㎛의 변위와 2.3μN의 발생력을 나타내었다. 이 마이크로액추에이터의 1차 공진주파수의 측정값의 23kHz이었다.

• 대한기계학회논문집B
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• 제27권2호
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• pp.236-242
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• 2003

Thermal bubbles find their diverse application areas in the MEMS (MicroElectroMechanial Systems) technology, including bubble jet printers, microactuators, micropumps, etc.. Especially, microactuators and micropumps, which use a microbubble growing by a controlled heat input, frequently involve mechanical and thermal interaction of the bubble with a solid structure, such as a cantilever beam and a membrane. Although the concept is experimentally verified that an internal pressure of the bubble can build up high enough to deflect a thin solid plate or a beam, the physics of the entire process have not yet been thoroughly explored. This work reports the experimental study of the growth of a thermal bubble while deflecting a thin cantilever beam. A physical model is presented to predict the elastic response of the cantilever beam based on the experimental measurements. The scaling law constructed through this work can provide a design guide for micro- and nano-systems that employ a thermal bubble for their actuation/pumping mechanism.

• 한국정밀공학회지
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• 제13권9호
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• pp.54-61
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• 1996

Because of its high energy density, the use of shape memory alloys(SMA) in designing microactuatiors is gaining much attention in recent years. Shape memory alloys can undergo a shape change at a low temperature with a small applied deformation force, and retain this deformation until they are heated, at which point they return to the original shape. This is called the shape memory effect(SME), and a plethora of alloys show this effect. Among them, TiNi-based alloys have relatively high electrical resistivity, which to develope helical-shape memory springs. These springs are used to develop fast protatonist/antagonist configuration actuators. The developed actuator has an actuation speed of 1 mm per 15 .approx. 20 ms and a minimum operating period of 2 sec.

• 한국재료학회:학술대회논문집
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• 한국재료학회 1999년도 춘계학술발표강연 및 눈문개요집
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• pp.41-41
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• 1999

• 드라이브 ㆍ 컨트롤
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• 제5권3호
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• pp.15-22
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• 2008

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.145-146
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• 1994

A SOI technology is promising for micromachining: high temperature operation, the fabrication easiness of sophisticated and 3D microstructures, radiation hardness, integrated sensors etc. This paper describes reviews of SOI technologies, and their applications microsensors and microactuators

• 대한기계학회논문집A
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• 제25권3호
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• pp.424-433
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• 2001

We present a new electrostatic repulsive-force microactuator using a lateral repulsive force induced by an asymmetric distribution of electrostatic field. The lateral repulsive force has been characterized by a simple analytical equation, derived from a finite element simulation. A set of repulsive force polysilicon microactuators has been designed and fabricated by a 4-mask surface-micromachining process. Static and dynamic micromechanical behavior of the fabricated microactuators has been measured at the atmospheric pressure for a varying bias voltage. The static displacement of the fabricated microactuator, proportional to the square of the DC bias voltage, is obtained as 1.27 $\mu\textrm{m}$ for the DC bias voltage of 140V. The resonant frequency of the repulsive-force microactuator increases from 11.7 kHz to 12.7 kHz when the DC bias voltage increases from 60V to 140V. The measured quality-factor varies from 12 to 13 for the bias volatge range of 60V∼140V. The characteristics of the electrostatic repulsive-force have been discussed and compared and compared with those of the conventional electrostatic attractive-force.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1857-1862
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• 2008

Resonant frequency tuning of micro devices is essential to achieve performance uniformity and high sensitivity. Previously reported frequency tuning methods using electrostatic force or mass deposition are not directly applicable to non-conducting polymer devices and have limitations such as dielectric breakdown or low tunable bandwidth. In this paper, thermally frequency-tunable microactuators with poly-dimethylsiloxane membranes are proposed. Permanent and/or nonpermanent frequency tunings are possible using a simple temperature control of the device. Resonant frequency and Q-factor variations of devices according to temperature change were studied using a micro heater and laser Doppler vibrometer. The initial resonant frequencies determined by polymer curing and hardening temperatures are reversibly tuned by thermal cycles. The measured resonant frequency of 9.7 kHz was tuned up by ${\sim}25%$ and Q-factor was increased from 14.5 to 27 as the micro heater voltage increased from 0 to 70 V.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1982-1984
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• 2002

The admittance of one-port electrostatic actuator are modeled using the steady-state sinusoidal response. Also the admittance of the differential type actuator is derived taking the practical conditions into consideration, although it has no admittance in ideal case. It is a function of biasing error, driving error, and capacitive mismatch including parasitic capacitors. The validity of the admittance model is proved by comparing between the modeled and measured admittances. The distortion in the frequency response curve measured by a capacitive sensor is analyzed and it is concluded that the admittance is the main cause of this distortion.