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Suigen, South Korea

Kim J.-M.,Chonbuk National University | Park H.-W.,Seoul National University | Jeong H.-G.,Microinfinity Co. | Kim Y.-K.,Seoul National University
Microelectronic Engineering | Year: 2012

This paper reports on the effects of a bottom electrode on the feed-through capacitance and a performance of a folded-beam MEMS resonator with a push-pull configuration. Generally, feed-through capacitance between driving and sensing ports should be minimized to reduce parasitic signals transmitted from driving ports to sensing ports. However, we found that a folded-beam MEMS resonator with a bottom electrode on a glass substrate has lower performance than a resonator without a bottom electrode, even though feed-through capacitance was reduced. The results of this paper showed that the reduction of the feed-through capacitance of a MEMS resonator is not always proportional to the resonator's performance. © 2012 Elsevier B.V. All rights reserved. Source

Kim H.-S.,Seoul National University | Jang Y.-H.,Seoul National University | Hwang Y.-S.,Microinfinity Co. | Kim Y.-K.,Seoul National University | Kim J.-M.,Chonbuk National University
2013 Transducers and Eurosensors XXVII: The 17th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS and EUROSENSORS 2013 | Year: 2013

A micromachined acceleration switch capable of adjusting the threshold acceleration to either higher or lower levels is firstly proposed. Comb drive actuators are used for the realization of threshold tuning. The acceleration switch is successfully fabricated using a silicon-on-glass process. The resonant frequency of the acceleration switch is measured to be 1.036 kHz, and the switch is turned on at 11 g without tuning voltage. It takes 9.7 ms for the switch to turn on, and the threshold acceleration is successfully increased to 19 g and decreased to 3 g by applying 30 V to pulling or pushing comb, respectively. © 2013 IEEE. Source

Song J.W.,Seoul National University | Lee J.-S.,Microinfinity Co. | An J.-E.,Agency for Defense Development | Park C.G.,Seoul National University
Review of Scientific Instruments | Year: 2015

The design, fabrication, and evaluation results of a MEMS piezoresistive differential pressure sensor fabricated by the dry etching process are described in this paper. The proposed sensor is designed to have optimal performances in mid-pressure range from 0 psi to 20 psi suitable for a precision air data module. The piezoresistors with a Wheatstone bridge structure are implanted where the thermal effects are minimized subject to sustainment of the sensitivity. The rectangular-shaped silicon diaphragm is adopted and its dimension is analyzed for improving pressure sensitivity and linearity. The bridge resistors are driven by constant current to compensate temperature effects on sensitivity. The designed differential pressure sensor is fabricated by using MEMS dry etching techniques, and the fabricated sensing element is attached and packaged in a Kovar package in consideration of leakage and temperature hysteresis. The implemented sensors are tested and evaluated as well. The evaluation results show the static RSS (root sum square) accuracy including nonlinearity, non-repeatability, and pressure hysteresis before temperature compensation is about 0.09%, and the total error band which includes the RSS accuracy, the thermal hysteresis, and other thermal effects is about 0.11%, which confirm the validity of the proposed design process. © 2015 AIP Publishing LLC. Source

Microinfinity Inc. | Date: 2011-04-14

Provided is a lawn mower for forming images. The lawn mower includes: an image input unit receiving an image to be formed in a lawn area; a position detection unit detecting position information of the lawn mower on a movement path of the lawn mower; a lawn mowing unit processing a lawn according to any one of a plurality of lawn processing patterns which corresponds to each position on the movement path while the lawn mower moves along the movement path; and a control unit analyzing the image received from the image input unit, determining a lawn processing pattern, which corresponds to the position information detected by the position detection unit, to express the image in the lawn area and controlling the lawn mowing unit according to the determined lawn processing pattern and independently of the movement path.

Provided is a rotary type distance estimation apparatus. The rotary type distance estimation apparatus includes: a signal transmission unit transmitting a signal for measuring a distance to an obstacle; a signal reception unit receiving the signal reflected by the obstacle; a distance calculation unit calculating the distance to the obstacle by processing the received signal; a rotation unit rotating a direction of the signal transmitted from the signal transmission unit; and a determination unit determining the direction of the signal within a predetermined angle range according to what number of times the received signal matches based on a rotation angle per sampling of the signal.

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