KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 10

Some of the metrics are blocked by your
consent settings
Sensing layer combination of vertically aligned ZnO nanorods and graphene oxide for ultrahigh sensitivity IDE capacitive humidity sensor
(2020-06-01)
Pongampai, Satana
;
Pengpad, Puttapon
;
Meananeatra, Rattanawan
;
Chaisriratanakul, Woraphan
;
Poyai, Amporn
An interdigitated electrode (IDE) capacitive humidity sensor fabricated on a silicon substrate was used to investigate sensing materials, which proved to be an ultrahigh-sensitivity humidity sensor. A sensing layer combination (SLC) between vertically aligned ZnO nanorods and optimal graphene oxide (GO) was prepared on the device and was tested as a humidity sensor. X-ray diffractometry (XRD) exhibited crystallized wurtzite structure of ZnO nanorods and transmission electron microscope (TEM) shown perfectly indexed hexagonal wurtzite ZnO structure dots position correspondence. A scanning electron microscope (SEM) was used to analyze ZnO nanorods/GO morphologies. Furthermore, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) clearly exhibited GO presence and hydrophilic functional groups (carboxyl, epoxy, and hydroxyl), respectively. The SLC prominently demonstrated ultrahigh sensitivity (up to 196.95% or 1.97 times from commercial sensor; HS1101, Humirel) and linear responses behavior with 0.96 for coefficient of determination. The device sensitivity obviously improved as steps of 40, 50, 60, 70, 80, and 90% RH at values of 1.09, 1.41, 1.51, 1.65, 1.80, and 1.91 times, respectively. The device also exhibited fast response (25 s) and short recovery times (17 s). Its hysteresis (6.58%) manifestly improved to 1.84 times. Moreover, repeatability and long-term ability of the device demonstrated high accuracy (range ±0.37pF) and durability. © 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Some of the metrics are blocked by your
consent settings
Study of Nitride Thickness on Sensitivity IDEs Humidity Sensor Based on Graphene Oxide Sensing
(2020-03-01)
Pongampai, Satana
;
Pengpad, Puttapon
;
Meananeatra, Rattanawan
;
Atiwongsangthong, Narin
;
Muanghlua, Rangson
An interdigitaged electrodes (IDEs) humidity sensor was patterned like a combs by lithography process based on silicon bulk substrate with different nitride thickness (50, 100 and 150 nm). This research studied an effect of thick nitride on sensitivity of IDEs humidity sensor based APTES adhesive layer with graphene oxide (GO) sensing material. The IDEs humidity sensor based on GO was comparatively examined all thick nitride conditions. Capacitance value of fresh IDEs humidity sensor shown not significant change all nitride thickness but it affected to sensitivity after GO coating due to high GO densified onto IDEs surface. Scanning Electron Microscope (SEM) was analyzed GO distribution and surface morphology. Raman spectroscopy clearly revealed the GO presence. The sensitivity from 50 to 80 %RH for optimal 100 nm thick nitride shows improvement to 2.78 and 1.27 times or 278.35% and 127.46% based on 50 and 150 nm thick nitride, respectively. Furthermore, the optimal condition of IDEs humidity sensor shows a little response and recovery times (11 and 7 sec), low hysteresis (3.21%), fine repeatability as well as high accuracy on long-term ability test. It clearly demonstrated for high sensitivity of nitride IDEs humidity sensor based on GO sensing film deposition.
Some of the metrics are blocked by your
consent settings
Ultrahigh sensitivity and linearity humidity sensor base on vertical alignment of ZnO nanorods sensing layer
(2019-03-01)
Pongampai, Satana
;
Pengpad, Puttapon
;
Meananeatra, Rattanawan
;
Horprathum, Mati
;
Chaisriratanakul, Woraphan
Capacitive humidity sensor was fabricated on CMOS technology with multiple parallel metals coplanar (interdigitage electrodes, IDEs) by lithography process base on silicon bulk substrate and coated Nickel-gold onto IDEs by electroless method. This paper proposed the IDEs humidity sensor with vertical alignment of zinc oxide (ZnO) nanorods on thick seed layer by sputtering process (IDEs/ZnO nanorods) for high sensitivity. ZnO nanorods structure and morphology were obtained by scanning electron microscope (SEM) and X-Ray diffractometer (XRD), respectively. The humidity sensors were comparatively examined properties before/after sputtering process. We have observed sputtering time for 3.0h with 100 nm thick seed layer effected to optimal vertical alignment of ZnO nanorods (length 480 nm) which shown high sensitivity (up to 1913.83%). Moreover, the IDEs/ZnO nanorods significantly improved on wide ranges relative humidity (30-90 %RH), fast response (up to 42.39%) and a little recovery times (16sec), precise repeatability as well as low hysteresis (18.22%). Finally, it demonstrated long-term stability and also exhibited a temperature dependence.
Some of the metrics are blocked by your
consent settings
Ultrahigh linear sensitivity of capacitive humidity sensor base on bilayer structure of graphene oxide
(2019-03-01)
Pongampai, Satana
;
Pengpad, Puttapon
;
Meananeatra, Rattanawan
;
Chaisriratanakul, Woraphan
;
Thitirungraung, Wisut
Capacitive humidity sensor is designed on interdigitage electrodes (IDEs) by lithography process for nice humidity absorption and desorption. This paper proposed the IDEs humidity sensor base on bilayers sensing of graphene oxide (GO) structure by dip coating method. Each GO layer is held by covalent-bond forces from adhesive layer. It demonstrates durable of sensing layer material. Raman spectroscopy analysis is exhibited on GO presence and scanning electron microscope (SEM) explored on the GO bilayers structure. The IDEs/GO bilayers humidity sensor demonstrated ultrahigh sensitivity (up to 2014.61%) and linear responses at relative humidity (RH) ranges 10 to 70% while IDEs/GO single layer showed exponential responses. Moreover, it significantly improved on response (12 sec) and recovery times (18sec), a little hysteresis (up to 46.77%) and stable repeatability. Finally, the durable of IDEs/GO bilayers humidity sensor is exhibited by long-term ability measurement (time period 35 days). Therefore, these characteristics of GO bilayers structure base on adhesive layer are clearly demonstrated high performances for alternatively used with humidity sensor applications.
Some of the metrics are blocked by your
consent settings
Influence of graphene oxide concentration on IDES capacitive humidity sensor response behavior
(2019-01-01)
Pongampai, Satana
;
Pengpad, Puttapon
;
Meananeatra, Rattanawan
;
Chaisriratanakul, Woraphan
;
Thitirungraung, Wisut
—Capacitive type humidity sensor was fabricated on CMOS technology by lithography process base on silicon p-substrate with Nitride passivation layer and designed on interdigitage electrodes (IDEs). This paper proposed the influence of various stock graphene oxide (GO) concentrations on humidity sensor responses behavior by drop coating method. The Raman spectroscopy is demonstrated for GO presence and scanning electron microscope (SEM) is exhibited the GO surface morphologies. The capacitance value is examined under different relative humidity (RH) ranges at 0.30% to 80% RH. The IDEs capacitive humidity sensor shows linear, polynomial and exponential responses behaviors for high, medium and low stock GO concentrations, respectively. The high stock GO concentration is significantly improved all dominant humidity sensor properties, especially the sensitivity at low RH (10%, 20%, 30% and 40% RH) which is improved up to 6683.65%, 2097.27%, 1984.91% and 1465.93%, respectively. Furthermore, it shows linear responses behavior by 0.991 for coefficient of determination of wide RH. Moreover, the IDEs capacitive humidity sensors are comparatively examined response/recovery times, hysteresis as well as repeatability. Finally, high stock GO concentration of humidity sensor is exhibited under various temperature operating ranges (20-50 degree Celsius). It clearly demonstrates for alternative applicability to use on humidity sensor applications.
Some of the metrics are blocked by your
consent settings
The magnetotransistor for 2-axis magnetic field measurement in CMOS technology
(2015-08-17)
Leepattarapongpan, Chana
;
Phetchakul, Toempong
;
Pengpad, Puttapon
;
Srihapat, Arckom
;
Jeamsaksiri, Wutthinan
This paper presents a magnetotransistor for detecting magnetic field in vertical and lateral directions (B<inf>Y</inf> and B<inf>Z</inf>) by relying on the difference between base and collector currents (ΔI<inf>CB</inf>). It was designed and fabricated using CMOS fabrication technology. The device structure consisted of one emitter, 4 collectors and 4 bases. The experiment showed that, at 10 mA of biasing current, the B<inf>Y</inf> and B<inf>Z</inf> direction sensitivity to magnetic field within the range of 0 - 400 mT are 0.7 and 1.35 %/T, respectively. The sensitivity at emitter current 20mA are 0.55 and 0.7 %/T for vertical and lateral magnetic field directions, respectively. This research on the magnetotransistor produced magnetic sensors with small size, high performance with wide range of applications.
Some of the metrics are blocked by your
consent settings
The increase sensitivity of PNP-magnetotransistor in CMOS technology
(2015-02-02)
Leepattarapongpan, Chana
;
Phetchakul, Toempong
;
Pengpad, Puttapon
;
Srihapat, Arckom
;
Jeamsaksiri, Wutthinan
This paper presents improve sensitivity of pnp-magnetotransistor for detect vertical magnetic field response. The device structure consisted of one emitter, four collectors and four bases. The four collectors are separate to form four terminals. The same is true for the four bases. The experiment showed that, at 2 and 4mA of biasing current, magnetic field in B<inf>Z</inf> direction sensitivity within the range of 0-400 mT are 0.045 and 0.09 mV/mT in single mode. The sensitivity of merge mode are 0.15 and 0.3 mV/mT. The magnetic field response of merge mode shows 4-time increase of the magnetic field sensitivity comparative to single mode.
Some of the metrics are blocked by your
consent settings
A merged magnetotransistor for 3-axis magnetic field measurement based on carrier recombination-deflection effect
(2014-01-01)
Leepattarapongpan, Chana
;
Phetchakul, Toempong
;
Penpondee, Naritchaphan
;
Pengpad, Puttapon
;
Srihapat, Arckom
This article presents a novel magnetotransistor based on carrier recombination-deflection effect for detecting magnetic field in three dimensions (B<inf>X</inf>, B<inf>Y</inf>, and B<inf>Z</inf>) by relying on the difference between base and collector currents (I<inf>CB</inf>). This device used low biasing current. It was designed and fabricated using CMOS fabrication technology. The device structure consisted of one emitter, 4 collectors and 4 bases. All four collector terminals were connected with each other. The same was true for the four base terminals. LOCOS oxide was grown to surround the emitter area to limit lateral carrier loss, and therefore reducing the overall biasing current. The experiment showed that, at 0.2 mA of biasing current, the B <inf>X</inf>, B<inf>Y</inf> and B<inf>-Z</inf> direction sensitivity to magnetic field within the range of 0-400 mT are 2, 5 and 14.5%/T, respectively. This research on the merged magnetotransistor produced magnetic sensors with small size, high performance with wide range of applications. © 2014 Elsevier Ltd.
Some of the metrics are blocked by your
consent settings
The low power 3D-magnetotransistor based on CMOS technology
(2011-12-01)
Leepattarapongpan, Chana
;
Phetchakul, Toempong
;
Penpondee, Naritchaphan
;
Pengpad, Puttapon
;
Srihapat, Arckom
This article presents a 3D magnetotransistor for detecting magnetic field in three dimensions (B <inf>X</inf>, B <inf>Y</inf>, and B <inf>Z</inf>) by relying on the difference between base and collector currents (ΔI <inf>CB</inf>). This device used low biasing current. It was designed and fabricated using CMOS fabrication technology. The device structure consisted of one emitter, 4 collectors and 4 bases. LOCOS oxide was grown to surround the emitter area to limit lateral carrier loss, and therefore reducing the overall biasing current. The experiment showed that, at 0.2 mA of biasing current, the BX, BY and BZ direction sensitivity to magnetic field within the range of 0 - 400 mT are 0.05, 0.07 and 0.145 mV/mT, respectively. © 2011 IEEE.
Some of the metrics are blocked by your
consent settings
The effect injection width and temperature-offset compensation of magnetotransistor
(2011-12-01)
Leepattarapongpan, Chana
;
Phetchakul, Toempong
;
Penpondee, Naritchaphan
;
Pengpad, Puttapon
;
Srihapat, Arckom
This paper presents effect of injection witdh on Magnetotransistor. Emitter area was confined by LOCOS and the injection window size was varied from 4, 5 to 10 microns. With bias current of 3 mA the window size 4 micron gives best sensitivity at 10mV/T. Measument linearity is 0.1 % full scale. voltage gain of 10 was used for minimizing temperature coefficient to be around 7.9 mV/°C measured from 25 to 125 °C. Temperature coefficient divided by sensitivity give us a relative temperature sensitivity of 7.9 % T/°C. Second magnetic sensor device has been used for temperature compensation. The second device was config as magnetic field immune then it was used as a temperature offset voltage reference. The added module reduces overall temperature sensitivy down to 0.3 % T/°C. © 2011 Published by Elsevier Ltd.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results