Digitally patterned resistive micro heater as a platform for zinc oxide nanowire based micro sensor

Kwon, Jinhyeong,Hong, Sukjoon,Kim, Gunho,Suh, Young D.,Lee, Habeom,Choo, Seung-Yeon,Lee, Daeho,Kong, Heejung,Yeo, Junyeob,Ko, Seung Hwan Elsevier BV * North-Holland 2018 Applied Surface Science Vol.447 No.-

<P><B>Abstract</B></P> <P>Among the various techniques for micro patterning of metal oxide nanowire, the resistive micro heater is promising technique due to the merit of localized and selective growth of sensing nanowire. In this study, we introduce a facile maskless fabrication of resistive micro heater using selective laser sintering of silver nanoparticle without using any conventional photolithography or vacuum deposition. By localized hydrothermal synthesis of ZnO nanowire using Joule heating of the resistive micro heater, the digitally patterned resistive micro heater is applied to the ZnO nanowire based micro UV sensor.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The digitally patterned resistive micro heater was fabricated using Ag nanoparticles. </LI> <LI> The ZnO NWs were successfully synthesized on the digitally patterned resistive micro heater. </LI> <LI> The growth rate in resistive micro heater was higher than the conventional synthesis. </LI> <LI> The resistive micro heater was used as a platform for ZnO NW based micro sensor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

다양한 형상을 갖는 마이크로 히터의 열특성에 관한 실험 및 전산해석적 연구

김진우(Jin Woo Kim),김재춘(Jae Choon Kim),이준엽(Jun Yub Lee),정진택(Jin Taek Chung) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

As a field of MEMS, micro-heater fabricated by Au is being introduced and developed in recent years. Previous studies about thermal properties of various forms of micro-heater were not sufficient. In this work, numerical and experimental analysis of the heat generation and the temperature distribution of micro-heater packages for 8 different geometric cases were studied. We fabricated a micro-heater package with silicon wafer, on which Cr/Au layer was laminated before 8 geometric forms of micro-heater were patterned. In each cases, temperature distribution was measured with IR thermal camera. According to the experimental results, which show a good agreement with the results analyzed by CFD, it was found that at 0.5W, the temperature of micro-heater chip which contained 20000㎛-long, serpentine shaped micro-heater was elevated to a relatively high temperature of 78℃. Consequently, we proposed a geometry of micro-heater which has effective thermal characteristics.

Temperature Distribution Measurement of Au Micro- Heater in Microfluidic Channel using IR Microscope

손정민,이준형,김정우,조영학 한국정밀공학회 2015 International Journal of Precision Engineering and Vol.16 No.2

The temperature control and measurement of micro-heater in microfluidic devices are very essential in various application fields suchas gas sensors, flow sensors and bio-sensors. In this study, the temperature of a micro-heater was measured while applying voltagesto micro-heaters with 100 μm width in microfluidic devices using infrared microscope. The Au micro-heater was fabricated onto asapphire substrate with good infrared transmission. In order to measure the temperature of Au micro-heater from the back side ofsapphire substrate using infrared microscope, the adhesion layer was not used during e-beam evaporation. To overcome the pooradhesion force between sapphire substrate and Au thin-film, thermal annealing was carried out at 400oC. This measurement methodenables us directly to measure the IR emissivity of Au micro-heater in aqueous media without infrared diffraction, absolution andreflection. Based on the calibration curve, we could measure the real temperature of Au micro-heater with 100 μm width atatmospheric environment and in aqueous media. Consequently, we could measure the temperature range at atmosphere and in DIwater. The companion computational fluid dynamics simulation studies showed that the measured temperature of Au micro-heater wasin accordance with the simulated results within 5 K in average sense.

The Fabrication of Micro-Heaters with Low-Power Consumption Using SOI and Trench Structures

Chung, Gwiy-Sang 대한금속학회 2002 METALS AND MATERIALS International Vol.8 No.4

This paper presents the optimized design, fabrication and thermal characteristics of micro-heaters for thermal MEMS (micro electro mechanical system) applications using SOI and trench structures. The micro-heaters are based on a thermal measurement principle and contain thermal isolation regions of l0㎛-thick Si membranes consisting of oxide-filled trenches in the SOI membrane rim. The micro-heaters were fabricated with Pt-RTD on the same substrate via the MgO buffer layer between the Pt thin-film and SiQ layer. The thermal characteristics of the micro-heaters with trench-free SOI membrane structure was 280℃ at an input power of 0.9 W; in the presence of 10 trenches, it was 580℃ due to the reduction of the external thermal loss. Therefore, a micro-heater with trenches in the SOI membrane rim structure provides a powerful and versatile alternative technology for enhancing the performance of micro-thermal sensors and actuators.

High-response and Low-power-consumption CO Micro Gas Sensor Based on Nano-powders and a Micro-heater

문승언,이재운,최낙진,이형근,양우석,김종대,박용주 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.60 No.2

In this research, a CO micro gas sensor was fabricated based on a micro-heater by using a tin oxide nano-powder for effective gas detection and a monitoring system with low power consumption and high sensitivity. Tin-oxide-based nano-powders were fabricated using a conventional method and their structural properties were examined by using the scanning electron microscope, X-ray diffractor,etc. Membrane type micro-heater based on Si substrate was fabricated by using complementary metal-oxide semiconductor (CMOS) compatible micro electro mechanical systems (MEMS) process by using bulk micromachining. The gas sensing properties for slurry-dropped tin oxide thick film device were measured for CO gas. The micro gas sensors showed high sensitivity and low power consumption, about 15 mW power consumption, 2 ppm CO could be detected.

SOI와 트랜치 구조를 이용한 초저소비전력형 미세발열체의 제작과 그 특성

정귀상,홍석우,이원재,송재성 한국전기전자재료학회 2001 전기전자재료학회논문지 Vol.14 No.3

This paper presents the optimized design, fabrication and thermal characteristics of micro-heaters for thermal MEMS (micro elelctro mechanical system) applications usign SOI (Si-on-insulator) and trench structures. The micro-heater is based on a thermal measurement principle and contains for thermal isolation regions a 10㎛ thick Si membrane with oxide-filled trenches in the SOI membrane rim. The micro-heater was fabricated with Pt-RTD (resistance thermometer device) on the same substrate by suing MgO as medium layer. The thermal characteristics of the micro-heater wit the SOI membrane is 280$\^{C}$ at input power 0.9W; for the SOI membrane with 10 trenches, it is 580$\^{C}$ due to reduction of the external thermal loss. Therefore, the micro-heater with trenches in SOI membrane rim provides a powerful and versatile alternative technology for improving the performance of micro-thermal sensors and actuators.

Improvement in transdermal drug delivery performance by graphite oxide/temperature-responsive hydrogel composites with micro heater

Yun, Jumi,Lee, Dae Hoon,Im, Ji Sun,Kim, Hyung-Il Elsevier 2012 Materials science & engineering. C, Materials for Vol.32 No.6

<P><B>Abstract</B></P><P>Transdermal drug delivery system (TDDS) was prepared with temperature-responsive hydrogel. The graphite was oxidized and incorporated into hydrogel matrix to improve the thermal response of hydrogel. The micro heater was fabricated to control the temperature precisely by adopting a joule heating method. The drug in hydrogel was delivered through a hairless mouse skin by controlling temperature. The efficiency of drug delivery was improved obviously by incorporation of graphite oxide due to the excellent thermal conductivity and the increased interfacial affinity between graphite oxide and hydrogel matrix. The fabricated micro heater was effective in controlling the temperature over lower critical solution temperature of hydrogel precisely with a small voltage less than 1V. The cell viability test on graphite oxide composite hydrogel showed enough safety for using as a transdermal drug delivery patch. The performance of TDDS could be improved noticeably based on temperature-responsive hydrogel, thermally conductive graphite oxide, and efficient micro heater.</P> <P><B>Graphical abstract</B></P><P>The high-performance transdermal drug delivery system could be prepared by combining temperature-responsive hydrogel, thermally conductive graphite oxide with improved interfacial affinity, and efficient micro heater fabricated by a joule heating method.<ce:figure id='f0005'></ce:figure></P><P><B>Highlights</B></P><P>► High performance of transdermal drug delivery system with an easy control of voltage. ► Improved thermal response of hydrogel by graphite oxide incorporation. ► Efficient micro heater fabricated by a joule heating method.</P>

마이크로히터에서 반주기 정현곡선의 열부하에 의한 비정상 열전달 연구

김명준(M. J. Kim),이희준(H. J. Lee) 한국전산유체공학회 2014 한국전산유체공학회지 Vol.19 No.4

A numerical study of transient conjugate heat transfer on micro heater in a micro-channel substrate under a sinusoidal heat load was conducted. It was found that the time constant is not affected by the maximum heating magnitude of the sinusoidal heat load. However, the time constant increases with low duration of the sinusoidal heating period and low Reynolds number. Moreover, there is a threshold where a heater temperature do not reach to time constant at low thermal diffusivity, low flow rate, and low pulse duration of the sinusoidal heating. The time constant should be considered for transient convective heat transfer under transient sinusoidal heat load in a micro heat sink.

사각 마이크로 히터위에서의 기포의 형성 및 거동

정정열(Jung-Yeul Jung),곽호영(Ho-Young Kwak) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

In this study, micro square heaters having dimensions of 65×65 μ㎡ and 100×100 μ㎡ were fabricated and bubble nucleation experiments on the heaters were performed. Bubble nucleation temperature was also measured using a bridge circuit and the photographs of bubble nucleation and subsequent growth were taken by a camera with a flash unit. Measured bubble nucleation temperatures were found to be closer to the superheat limit of working fluid (FC-72). Also quasi-1D analyses for the square heaters were performed. The quasi-1D analysis yielded proper temperature distribution of the square heater at steady state, however failed to predict the temperature rise up to the steady state. Similar time dependent temperature can be obtained with proper value of thermal diffusivity. For the 100×100 μ㎡ square heater, nucleation of several bubbles was observed while only one bubble was observed to be nucleated on 65×65 μ㎡ heater.

Low-Power-Consumption and High-Sensitivity NO2 Micro Gas Sensors Based on a Co-Planar Micro-Heater Fabricated by Using a CMOS-MEMS Process

문승언,J.-W. Lee,박소정,J. Park,K.-H. Park,J. Kim 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.56 No.1

Small-scale, low-power-consumption, and high-sensitivity NO2 gas sensors based on ZnO nanorods are reported in this work. To activate the chemical absorption and desorption for NO2gas, we embedded co-planar micro-heater in a micro gas sensor, that was made by using a Complementary Metal–oxide–semiconductor compatible Microelectromechanical Systems(CMOS-MEMS)process. To acquire simple fabrication and low fabrication cost, we located the micro-heater and the sensing electrode in the same plane. High-quality single-crystalline ZnO nanorods were selectively grown by using photolithography and a hydrothermal method. Their structural properties were confirmed by using X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy microanalysis (EDAX), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The temperature-dependent current-voltage characteristics were measured to optimize the operating temperature of the fabricated devices as a chemical gas sensor. To test the possibility for use as chemical sensor, we measured the NO2 gas response.