• Korean Journal of Acupuncture
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• v.24 no.3
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• pp.105-116
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• 2007

Objectives : This study was performed to determine whether a pulse analyzer using array piezoresistive sensor was useful to characterize the variables of pulse wave of hypertentive patients (HT) , compared with those of healthy subjects. Methods : One hundred twenty two subjects participated in this study. Sixty nine subjects had hypertension and fifty three subjects had no specific history or disease associated with hypertension. We used automatic pulse analyzer with array piezoreslstive sensor. Results : Calibrated in Chon, no specific differences was between HT group and the healthy group. Calibrated in Gwan. sum of pulse pressure (SPP) of HT group was higher than that of the healthy group. Calibrated in Cheek, mean of height of main peak (Mm) and height of main peak (h1) of HT group were higher than those of the healthy group. Conclusions : Pulse analyzer was useful to determine the risk degree or development possibility of hypertension.

• Journal of Sensor Science and Technology
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• v.8 no.3
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• pp.253-258
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• 1999

This paper is written for the purpose of obtaining the information about the weather easily by the development of weather forecast system sensing temperature, humidity, and atmospheric pressure as key information. For this, data is obtained from the Weather Bureau, and analyzed in order to set a standard of weather forecast from the collected data. The pressure sensor and temperature-humidity sensor are fabricated using the piezoresistive effect of semiconductor, which are used to collect data. The weather forecast system is made using microprocessor.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.05a
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• pp.105-109
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• 2000

Micronization of sensor is a trend of the silicon sensor development with regard to a piezoresistive silicon pressure sensor the size of the pressure sensor diaphragm have become smaller year by year and a microaccelerometer with a size less than 200-300${\mu}m$ has been realized. In this paper we study some of the micromachining processes of SOI(silicon on insulator)for the microaccelerometer and their subsequent processes which might affect thermal loads. The finite element method(FEM) has been a standard numerical modeling technique extensively utilized in structural engineering discipline for design of SOI wafers. Successful thermal behaviors analysis and design of the SOI wafers based on the tunneling current concept using SOI wafer depend on the knowledge abut normal mechanical properties of the SCS(single crystal silicon)layer and their control through manufacturing process

• Journal of Power System Engineering
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• v.5 no.4
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• pp.11-17
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• 2001

Micronization of sensor is a trend of the silicon sensor development with regard to a piezoresistive silicon pressure sensor, the size of the pressure sensor diaphragm have become smaller year by year, and a microaccelerometer with a size less than $200{\sim}300{\mu}m$ has been realized, In this paper, we study some of the bonding processes of SCS(single crystal silicon) insulator wafer for the microaccelerometer. and their subsequent processes which might affect thermal loads. The finite element method(FEM) has been a standard numerical modeling technique extensively utilized in micro structural engineering discipline for design of SCS insulator wafers. Successful temperature distribution analysis and design of the SCS insulator wafers based on the tunneling current concept using microaccelerometer depend on the knowledge about normal mechanical properties of the SCS and $SiO_2$ layer and their control through manufacturing processes.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1229-1230
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• 2015

Monitoring of mechanical properties of tissues as well as direction/quantities of forces is considered as an essential way for disease diagnosis and haptic feedback systems. There are extensively increasing interests for measuring normal/shear force and touch feelings, especially for surgery systems. Highly sensitive and flexible tactile sensor is needed in palpation for detecting cancer cyst as well as real time pressure monitoring in minimally invasive surgery (MIS). Importantly, MEMS technique with miniaturized fabrication technique is essential for the on-chip integration with biopsy and biomedical grasper. Here, we propose the flexible tactile sensor with high sensitivity based on piezoresistive effect. We analyzed the sensitivity according to the pressure and directions and showed the ability of discrimination of the different materials surfaces, illustrating the feasibility of the flexible tactile sensor for biomedical grasper by mimicking human skin.

• Journal of IKEEE
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• v.1 no.1 s.1
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• pp.1-10
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• 1997

It is well-known that rectangular bulk-Si sensors prepared by etch or epi etch-stop micromachining technology are already in practical use today, but the conventional bulk-Si sensor shows some drawbacks such as large chip size and limited applications as silicon sensor device is to be miniaturized. We consider a circular-shape SOI(Silicon-On-Insulator) micro-cavity technology to facilitate multiple sensors on very small chip, to make device easier to package than conventional sensor like pressure sensor and to provide very high over-pressure capability. This paper demonstrates the cross-functional results for stress analyses(targeting $5{\mu}m$ deflection and 100MPa stress as maximum at various applicable pressure ranges), for finding permissible diaphragm dimension by output sensitivity, and piezoresistive sensor theory from two-type SOI structures where the double SOI structure shows the most feasible deflection and small stress at various ambient pressures. Those results can be compared with the ones of circular-shape bulk-Si based sensor$^{[17]}. The SOI micro-cavity formed the sensors is promising to integrate with calibration, gain stage and controller unit plus high current/high voltage CMOS drivers onto monolithic chip.

• Journal of Sensor Science and Technology
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• v.31 no.3
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• pp.139-144
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• 2022

Advanced tactile sensors are receiving significant attention in various industries such as extended reality, electronic skin, organic user interfaces, and robotics. The capabilities of advanced tactile sensors require a variety of functions, including position sensing, pressure sensing, and material recognition. Moreover, they should comsume less power and be bio-friendly with human contact. Recently, a tactile sensor based on the triboelectrification effect was developed. Triboelectric tactile sensors have the advantages of wide material availability, simple structure, and low manufacturing cost. Because they generate electricity by contact, they have low power consumption compared to conventional tactile sensors such as capacitive and piezoresistive. Furthermore, they have the ability to recognize the contact material as well as execute position and pressure sensing functions using the triboelectrification effect. The aim of this study is to introduce the progress of research on triboelectrification-based tactile sensors with various functions such as position sensing, pressure sensing and contact material recognition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.888-891
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• 2003

This paper describes on the fabrication and characteristics of micro ceramic thin-film type pressure sensors based on Ta-N strain-gauges for high-temperature applications. The Ta-N thin-film strain-gauges are deposited onto thermally oxidized Si diaphragms by RF sputtering in an argon-nitrogen atmosphere($N_2$ gas ratio: 8 %, annealing condition: $900^{\circ}C$, 1 hr.), Patterned on a wheatstone bridge configuration, and use as pressure sensing elements with a high stability and a high gauge factor. The sensitivity is $1.097{\sim}1.21mV/V.kgf/cm^2$ in the temperature range of $25{\sim}200^{\circ}C$ and the maximum non-linearity is 0.43 %FS. The fabricated pressure sensor presents a lower TCR, non-linearity than existing Si piezoresistive pressure sensors. The fabricated micro ceramic thin-film type pressure sensor is expected to be usefully applied as pressure and load sensors that is operable under high-temperature environments.

• Journal of Sensor Science and Technology
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• v.7 no.3
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• pp.171-178
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• 1998

Silicon piezoresistive absolute pressure sensor for gas leakage alarm system was developed. This sensor must operate normally in the range of $0{\sim}600\;mmH_{2}O$ pressure, and $0{\sim}100^{\circ}C$ temperature. To make the most of this sensor for gas leakage alarm system, gas must not leak from the sensor itself when the diaphragm of the sensor fractures. Thus, the sealed diaphragm cavity was anodically bonded to pyrex 7740 glass under the condition of $10^{-4}$ torr, at $400^{\circ}C$. The sensitivity of developed sensor was $4.06{\mu}V/VmmH_{2}O$ for $600\;mmH_{2}O$ full-scale pressure range. And temperature compensation method of this sensor is to change bridge-in put-voltage linearly in proportion to the temperature variation by using diode(PXIN4001) or Al thin film resistor. By these methods the temperature effect in the range of $0{\sim}100^{\circ}C$ was compensated over 80 % for offset drift, 95 % for sensitivity.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.65-74
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• 2021

With recent innovations in the ICT industry, the demand for wearable sensing devices to recognize and respond to biological signals has increased. In this study, a three-dimensional (3D) spacer fabric was embedded in a single-wall carbon nanotube (SWCNT) dispersive solution through a simple penetration process to develop a monolayer piezoresistive pressure sensor. To induce electrical conductivity in the 3D spacer fabric, samples were immersed in the SWCNT dispersive solution and dried. To determine the electrical properties of the impregnated specimen, a universal testing machine and multimeter were used to measure the resistance of the pressure change. Moreover, to examine the changes in the electrical properties of the sensor, its performance was evaluated by varying the concentration, number of penetrations, and thickness of the specimen. Samples that penetrated twice in the SWCNT distributed solution of 0.1 wt% showed the best performance as sensors. The 7-mm thick sensors showed the highest GF, and the 13-mm thick sensors showed the widest operating range. This study confirms the effectiveness of the simple process of fabricating smart textile sensors comprising 3D spacer fabrics and the excellent performance of the sensors.