{"id":3739,"date":"2019-06-11T10:43:47","date_gmt":"2019-06-11T05:13:47","guid":{"rendered":"http:\/\/iap.iisc.ac.in\/~abha\/?p=3739"},"modified":"2020-07-07T00:47:56","modified_gmt":"2020-07-06T19:17:56","slug":"nanoelectronics-and-optoelectronics-for-electronic-nose","status":"publish","type":"post","link":"https:\/\/iap.iisc.ac.in\/~abha\/nanoelectronics-and-optoelectronics-for-electronic-nose\/","title":{"rendered":"Nanoelectronics and Optoelectronics for Electronic Nose"},"content":{"rendered":"\n

In this area, we are exploiting interfacial properties of two-dimensional and one-dimensional interfaces of various heterostructures. Our aim is to fabricate highly sensitive sensing platform for the detection of multiple gases for the air pollution monitoring. In this process we use several algorithms to integrate sensors at room temperature. We were able to successfully integrate sensor for the detection of compressed natural gas (CNG) in collaboration with Gas Authority of India Limited (GAIL). These compact room temperature sensors are applicable to detect leakage of gas in house-hold, manufacturing and storage units, transport pipelines etc. We built a microscopic platform of field effect transistors (FET) for the large array of electronic sensors to mimic neurons in the olfactory system for the detection of multiple gases present in the environment. Machine learning algorithms are implemented for the large data analysis. The laboratory has unique facility to create an environment where molecular detection of various gases is possible upto parts per trillion scale. <\/p>\n\n\n\n

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Nanoscale heterojunctions of rGO-MoS2<\/sub> composites for nitrogen dioxide sensing at room temperature <\/strong><\/p>\n\n\n\n

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Figure: Cyclic response of rGO-MoS2<\/sub>-Ag\n(GMA)  towards 1 ppm of NO2<\/sub>\nfor 4 cycles. (b) Sensor response of GMA towards various test gases at room temperature\nshowing selectivity to NO2<\/sub>.<\/p>\n\n\n\n

Reference: Nano\nExpress 1 (2020) 010003<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/2632-959X\/ab7491<\/a><\/p>\n\n\n\n

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Modified fermi level in strontium nanoparticles\ndecorated reduced graphene oxide for wide concentration detection of  nitrogen dioxide at room temperature <\/strong><\/p>\n\n\n\n

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Figure: (a) Sensor response of rGO-Sr towards various\ntest gases at room temperature showing selectivity toNO2<\/sub>. (b)\nSchematic showing the promotion of fermi level in rGO assisted by Sr. Plot of\nsensor response versus concentration for both the devices. (d) Dynamic sensor\nresponse of rGO and rGO-Sr versus time towards varying concentrations of NO2<\/sub>\nwith UV aided complete desorption.<\/p>\n\n\n\n

Reference: Mater. Res. Express 6 (2019) 065611<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/2053-1591\/ab0d3a<\/a><\/p>\n\n\n\n

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Influence of charge traps in carbon nanodots on gas\ninteraction <\/strong><\/p>\n\n\n\n

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Figure: (a) HRTEM image of carbon nanodotss indicating\na lattice parameter of 0.18 nm and 0.21 nm. (b) Cyclic response (current) to\ndifferent concentrations of NO2<\/sub>. (c) I\u2013V measurements obtained by\nsweeping voltage in the range from ?2 to 2 V in both forward and reverse\ndirections. Measurement curves were obtained at room temperature and at an\nelevated temperature of 150 \u00b0C. (d) Energy band diagram of carbon dots without\nthe presence of water molecules (removal of water molecules either by heat at\nan elevated temperature or by gas) indicating an enhanced potential barrier for\nelectron flow.<\/p>\n\n\n\n

Reference: Nanotechnology\n28 (2017) 135206<\/p>\n\n\n\n

https:\/\/doi.org\/10.1088\/1361-6528\/aa5fbc<\/a><\/p>\n\n\n\n

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Tailored nitrogen dioxide sensing response of three-dimensional\ngraphene foam<\/strong><\/p>\n\n\n\n

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Figure: (a) SEM image of rGO foam, inset shows the NO2<\/sub>\nsensing response. (b) Three-dimensional XT micrographs of GO foam. two\ndimensional images of different slices of the above foam from left to right.<\/p>\n\n\n\n

Reference: Sensors and Actuators B 222 (2016) 21\u201327<\/p>\n\n\n\n

https:\/\/doi.org\/10.1016\/j.snb.2015.08.041<\/a><\/p>\n\n\n\n

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Water-responsive carbon\nnanotubes for selective detection of toxic gases<\/strong><\/p>\n\n\n\n

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Figure: (a) Schematic of the experimental set-up used\nfor converting hydrophobic CNT to hydrophilic. (b) Variation in contact angle\nof the water drop on both hydrophobic (top) and hydrophilic sample (below)\nevaluated with the time. In hydrophilic sample, water was confined within the\nbulk structure, which percolates into the bulk of the forest within a few\nseconds. Circuit diagram of the proposed gas alarm prototype based on bulk CNT.\nGreen LED glows in the absence of gas and red LED glows after bulk CNT curls up\nupon exposure to NH3 gas, while eventually breaking a specific part of the\ncircuit.<\/p>\n\n\n\n

Reference: APPLIED PHYSICS LETTERS 106, 113108 (2015)<\/p>\n\n\n\n

https:\/\/doi.org\/10.1063\/1.4916211<\/a><\/p>\n\n\n\n

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Two-dimensional van der Waals FET devices for NO2<\/sub>\nsensing<\/strong><\/p>\n\n\n\n

Two dimensional heterointerfaces are currently being\nstudied for NO2<\/sub> sensing using \nfield effect transistors. <\/p>\n\n\n\n

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Figure: (a) Field effect transistor device (b) Density\nfunctional theory simulations. <\/p>\n\n\n\n

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Carbon nanotube based\nmultifunctional flame sensor<\/strong><\/p>\n\n\n\n

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(a) Schematic\nshows the experimental set-up used for sensing flame using MWCNT sensor. (b)\nand (c) Show the lateral and longitudinal directions of the sensor measurements.\n(d) Cyclical voltage response of the MWCNT sensor device while applying a fixed\nbias current and it is exposed to the flame that was kept at 4 cm distance from\nthe sensor in the lateral direction.<\/p>\n\n\n\n

Reference: Sensors and Actuators B 192\n(2014) 594\u2013 600.<\/p>\n\n\n\n

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Graphene based\nmultifunctional flame sensor<\/strong><\/p>\n\n\n\n

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Circuit setup for the sensor and Variation\nof normalized resistance change with time on exposure to flame at varying\ndistances of the flame from the sensor vertically.<\/p>\n\n\n\n

Reference: Nanotechnology 26 (2015) 195502.<\/p>\n\n\n\n

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Chemical vapor detection\nusing nonlinear electrical properties of carbon nanotube bundles<\/strong><\/p>\n\n\n\n

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Scanning\nelectron microscope image of the CNT dispersed gold electrodes used for the\nsensing of organic analytes. The inset shows microstructure of the CNT mat in\nbetween the electrodes. (b) Schematic of the experimental setup used for the\nCNT sensor. Differential conductance plotted against bias voltage for ethanol\nas analyte (before and after analyte exposure). The inset shows the differential\nconductance plot during the chemical exposure. (b) Percentage-change in\ndifferential conductance before, during and after analyte exposure, a\ncomparison of all analytes exposed to the CNT mat.<\/p>\n\n\n\n

Reference: Nanotechnology 25 (2014) 025708<\/p>\n\n\n\n

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In this area, we are exploiting interfacial properties of two-dimensional and one-dimensional interfaces of various heterostructures. Our aim is to fabricate highly sensitive sensing platform for the detection of multiple gases for the air pollution monitoring. In this process we use several algorithms to integrate sensors at room temperature. We were able to successfully integrate […]<\/p>\n","protected":false},"author":1,"featured_media":3911,"parent":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[39],"tags":[],"class_list":["post-3739","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"acf":[],"_links":{"self":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3739","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/comments?post=3739"}],"version-history":[{"count":31,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3739\/revisions"}],"predecessor-version":[{"id":4182,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/posts\/3739\/revisions\/4182"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/media\/3911"}],"wp:attachment":[{"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/media?parent=3739"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/categories?post=3739"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/iap.iisc.ac.in\/~abha\/wp-json\/wp\/v2\/tags?post=3739"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}