• Transactions on Electrical and Electronic Materials
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• 제13권5호
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• pp.215-220
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• 2012

Miniature ultrasonic and tactile sensors on Si substrate have been proposed, fabricated and characterized to detect objects for a dexterous robot. The ultrasonic sensor consists of piezoelectric PZT thin film on a Pt/Ti/$SiO_2$ and/or Si diaphragm fabricated using a micromachining technique; the ultrasonic sensor detects the piezoelectric voltage as an ultrasonic wave. The sensitivity has been enhanced by improving the device structure, and the resonant frequency in the array sensor has been equalized. Position detection has been carried out by using a sensor array with high sensitivity and uniform resonant frequency. The tactile sensor consists of four or three warped cantilevers which have NiCr or $Si:B^+$ piezoresistive layer for stress detection. Normal and shear stresses can be estimated by calculation using resistance changes of the piezoresitive layers on the cantilevers. Gripping state has been identified by using the tactile sensor which is installed on finger of a robot hand, and friction of objects has been measured by slipping the sensor.

• 한국가시화정보학회지
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• 제9권2호
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• pp.34-39
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• 2011

This paper presents a novel direct fabrication method of the thin metal film RTD temperature sensor array on an arbitrary curved surface by using MEMS technology to measure a distributed temperature field up to $300^{\circ}C$ without disturbing a fluid flow. In order to overcome the difficulty in the three dimensional photography of sensor patterning, the UV pre-irradiated photosensitive dry film resist technology has been developed newly. This method was applied to the fabrication of the temperature sensor array on a glass tube, which is arranged parallel and transverse to a main flow. Gold was used as a temperature sensing material. The resistance change was measured in a thermally controlled oven by increasing the environmental temperature. The linear increase in resistance change and a constant slope were obtained. Also, the sensitivity of each RTD temperature sensor was evaluated.

• 정보저장시스템학회논문집
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• 제1권1호
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• pp.73-77
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• 2005

In this paper, a new silicon nitride cantilever integrated with silicon heater and piezoelectric sensor has been firstly developed to improve the uniformity of the initial bending and the mechanical stability of the cantilever array for thermo-piezoelectric SPM(scanning probe microscopy) -based data storages. This nitride cantilever shows thickness uniformity less than $2\%$. Data bits of 40 nm in diameter were recorded on PMMA film. The sensitivity of the piezoelectric sensor was 0.615 fC/nm after poling the PZT layer. For high speed operation, 128${\times}$128 probe array was developed.

• 전자통신동향분석
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• 제34권4호
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• pp.76-88
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• 2019

With advances in olfactory sensor technologies, the number of reports on various intelligent applications using multiple sensors (sensor arrays) are continuously increasing for fields such as medicine, environment, security, etc. For intelligent and point-of-care applications, it is not only important for the sensor technology to perform chemical or physical measurements rapidly and accurately, but it is also important for artificial intelligence technology to recognize and quantify specific chemicals or diagnose diseases such as lung cancer and diabetes. In particular, great advances in pattern recognition technologies, including deep learning algorithms, as well as sensor array technologies, are expected to enhance the potential of various types of olfactory intelligence applications, including early cancer diagnosis, drug seeking, military operations, and air pollution monitoring.

• 센서학회지
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• 제25권5호
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• pp.349-353
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• 2016

Recently, research on bolometer-type uncooled infrared image sensor which is made for industrial applications has been increasing. In general, it is difficult to calibrate fixed pattern noise (FPN) of bolometer array. In this paper, average-current calibration algorithm is presented for reducing bolometer resistance offset. A resistor which is produced by standard CMOS process, on the average, has a deviation. We compensate for deviation of each resistor using average-current calibration algorithm. The proposed algorithm has been implemented by a chip which is consisted of a bolometer pixel array, average current generators, current-to-voltage converters (IVCs), a digital-to-analog converter (DAC), and analog-to-digital converters (ADCs). These bolometer-resistor array and readout circuit were designed and manufactured by $0.35{\mu}m$ standard CMOS process.

• 센서학회지
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• 제13권5호
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• pp.378-382
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• 2004

A micromachined fluidic structure for the introduction of liquid samples into a chip-based sensor array composed of individually addressable polymeric microbeads has been developed. The structure consists of a separately attached cover glass, a single silicon chip having micromachined channels and microbead storage cavities, and a glass carver. In our sensor array, transduction occurs via colorimetric and fluorescence changes to receptors and indicator molecules that are covalently attached to termination sites on the polymeric microbeads. Data streams are acquired for each of the individual microbeads using a CCD. One of the key parts of the structure is a passive fluid introduction system driven only by capillary force. The velocity of penetration of a horizontal capillary for the device having a rectangular cross section has been derived, and it is quite similar to the Washburn Equation calculated for a pipe with a circular cross section having uniform radius. The test results show that this system is useful in a ${\mu}$-TAS and biomedical applications.

• 산업기술연구
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• 제27권B호
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• pp.125-128
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• 2007

This paper presents Spectral-Domain optical measurement system using self-fabricated CCD sensor driver. The light source is a high brightness white LED and the detector is a 2048 array typed CCD image sensor. I have fabricated the CCD sensor driver to generate four pulse signals, which are the CCD-driving pulses. Using this Spectral Domain optical measurement system, the distance value between the reference mirror and the sample mirror can be obtained successfully.

• 센서학회지
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• 제17권2호
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• pp.106-113
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• 2008

Perceiving a 3D moving target is important for automated machines including robots in a factory. Although stereovision or ultrasonic ranging is often employed for the purpose, the former requires high-cost systems, and the latter suffers from low-resolution. In this paper, we propose a PSD sensor array to acquire the 3D profile of an object conveyed by a belt. Rectangular parallelepiped target objects at random positions and orientations are assumed. Nine PSD sensors are configured in a $3{\times}3$ array above the belt, and fired in a sequence so that cross-talk can be avoided. Time gaps among sensor readings are compensated to get a result that is obtainable when sensors' measurements are made simultaneously along a sensing line. The system designed is tested with various objects in experiments.

• JSTS:Journal of Semiconductor Technology and Science
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• 제6권4호
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• pp.270-274
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• 2006

A color filter array (CFA) helps a single electrical image sensor to recognize color images. The Red-Green-Blue (RGB) Bayer CFA is commonly used, but the amount of the light which arrives at the photodiode is attenuated with this CFA. Red-White-Blue (RWB) CFA increases the amount of the light which arrives at photodiode by using White (W) pixels instead of Green (G) pixels. However, white pixels are saturated earlier than red and blue pixels. The pseudo multiple capture scheme and the corresponding RWB CFA were proposed to overcome the early saturation problem of W pixels. The prototype CMOS image sensor (CIS) was fabricated with $0.35-{\mu}m$ CMOS process. The proposed CIS solves the early saturation problem of W pixels and increases the dynamic range.

• 센서학회지
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• 제19권3호
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• pp.246-257
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• 2010

Autonomous guided robot navigation which consists of following unknown paths and avoiding unknown obstacles has been a fundamental technique for unmanned robots in outdoor environments. The unknown path following requires techniques such as path recognition, path planning, and robot pose estimation. In this paper, we propose a novel sensor fusion system for autonomous guided robot navigation in outdoor environments. The proposed system consists of three monocular cameras and an array of nine infrared range sensors. The two cameras equipped on the robot's right and left sides are used to recognize unknown paths and estimate relative robot pose on these paths through bayesian sensor fusion method, and the other camera equipped at the front of the robot is used to recognize abrupt curves and unknown obstacles. The infrared range sensor array is used to improve the robustness of obstacle avoidance. The forward camera and the infrared range sensor array are fused through rule-based method for obstacle avoidance. Experiments in outdoor environments show the mobile robot with the proposed sensor fusion system performed successfully real-time autonomous guided navigation.