{"id":1875,"date":"2023-04-26T14:13:56","date_gmt":"2023-04-26T14:13:56","guid":{"rendered":"https:\/\/micro.bilkent.edu.tr\/?page_id=1875"},"modified":"2023-06-02T12:29:26","modified_gmt":"2023-06-02T12:29:26","slug":"research-2","status":"publish","type":"page","link":"https:\/\/micro.bilkent.edu.tr\/?page_id=1875","title":{"rendered":"Research"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"1875\" class=\"elementor elementor-1875\">\n\t\t\t\t\t\t\t<div class=\"elementor-element elementor-element-6439648 e-con-boxed e-flex e-con\" data-id=\"6439648\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-d279801 elementor-widget elementor-widget-spacer\" data-id=\"d279801\" data-element_type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.13.0 - 24-04-2023 *\/\n.elementor-column .elementor-spacer-inner{height:var(--spacer-size)}.e-con{--container-widget-width:100%}.e-con-inner>.elementor-widget-spacer,.e-con>.elementor-widget-spacer{width:var(--container-widget-width,var(--spacer-size));--align-self:var(--container-widget-align-self,initial);--flex-shrink:0}.e-con-inner>.elementor-widget-spacer>.elementor-widget-container,.e-con-inner>.elementor-widget-spacer>.elementor-widget-container>.elementor-spacer,.e-con>.elementor-widget-spacer>.elementor-widget-container,.e-con>.elementor-widget-spacer>.elementor-widget-container>.elementor-spacer{height:100%}.e-con-inner>.elementor-widget-spacer>.elementor-widget-container>.elementor-spacer>.elementor-spacer-inner,.e-con>.elementor-widget-spacer>.elementor-widget-container>.elementor-spacer>.elementor-spacer-inner{height:var(--container-widget-height,var(--spacer-size))}<\/style>\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5b3765d elementor-widget elementor-widget-heading\" data-id=\"5b3765d\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.13.0 - 24-04-2023 *\/\n.elementor-heading-title{padding:0;margin:0;line-height:1}.elementor-widget-heading .elementor-heading-title[class*=elementor-size-]>a{color:inherit;font-size:inherit;line-height:inherit}.elementor-widget-heading .elementor-heading-title.elementor-size-small{font-size:15px}.elementor-widget-heading .elementor-heading-title.elementor-size-medium{font-size:19px}.elementor-widget-heading .elementor-heading-title.elementor-size-large{font-size:29px}.elementor-widget-heading .elementor-heading-title.elementor-size-xl{font-size:39px}.elementor-widget-heading .elementor-heading-title.elementor-size-xxl{font-size:59px}<\/style><h2 class=\"elementor-heading-title elementor-size-default\"><h2 data-elementor-setting-key=\"title\" data-pen-placeholder=\"Type Here...\" style=\"font-style: normal;\">Universal Gas Sensing with Acoustic Coupling in a Cavity<\/h2><\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-225f9d5 elementor-widget elementor-widget-text-editor\" data-id=\"225f9d5\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.13.0 - 24-04-2023 *\/\n.elementor-widget-text-editor.elementor-drop-cap-view-stacked .elementor-drop-cap{background-color:#69727d;color:#fff}.elementor-widget-text-editor.elementor-drop-cap-view-framed .elementor-drop-cap{color:#69727d;border:3px solid;background-color:transparent}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap{margin-top:8px}.elementor-widget-text-editor:not(.elementor-drop-cap-view-default) .elementor-drop-cap-letter{width:1em;height:1em}.elementor-widget-text-editor .elementor-drop-cap{float:left;text-align:center;line-height:1;font-size:50px}.elementor-widget-text-editor .elementor-drop-cap-letter{display:inline-block}<\/style>\t\t\t\t<p><span style=\"font-style: inherit; font-weight: inherit; color: rgba(0, 0, 0, 0.87); font-family: Roboto, -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif; font-size: 19.2px;\">This project has received funding from the European Union&#8217;s Horizon 2020 research and innovation programme under the Marie Sk\u0142<\/span><span style=\"font-style: inherit; font-weight: inherit; color: rgba(0, 0, 0, 0.87); font-family: Roboto, -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif; font-size: 19.2px;\">o<\/span><span style=\"font-style: inherit; font-weight: inherit; color: rgba(0, 0, 0, 0.87); font-family: Roboto, -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif; font-size: 19.2px;\">dowska-Curie grant agreement No 101038092.<\/span><\/p><p><span style=\"font-style: inherit; font-weight: inherit; color: rgba(0, 0, 0, 0.87); font-family: Roboto, -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif; font-size: 19.2px;\"><br><\/span><\/p>\n<p><span style=\"font-style: inherit; font-weight: inherit; color: rgba(0, 0, 0, 0.87); font-family: Roboto, -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif; font-size: 19.2px;\">With current gas sensing technologies, sensors have to be developed individually for each gas under test. Most sensors available today rely on one of two techniques:<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-e9b7ee8 e-con-boxed e-flex e-con\" data-id=\"e9b7ee8\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-e9354f5 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"e9354f5\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<style>\/*! elementor - v3.13.0 - 24-04-2023 *\/\n.elementor-widget-image{text-align:center}.elementor-widget-image a{display:inline-block}.elementor-widget-image a img[src$=\".svg\"]{width:48px}.elementor-widget-image img{vertical-align:middle;display:inline-block}<\/style>\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"736\" height=\"685\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-1.png\" class=\"attachment-large size-large wp-image-1973\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-1.png 736w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-1-300x279.png 300w\" sizes=\"(max-width: 736px) 100vw, 736px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-615b236 e-con-boxed e-flex e-con\" data-id=\"615b236\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-53ae72e elementor-widget elementor-widget-text-editor\" data-id=\"53ae72e\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<ul><li><span style=\"box-sizing: inherit; font-weight: bold;\">Chemical sensing<\/span>: The gas of interest is passed over a substrate which reacts selectively with one or multiple types of gas. An electric current results which can be amplified to yield the result. Among chemical sensor types are metal oxide semiconductor, polymers and carbon nanotube sensors.<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1f5c238 elementor-widget elementor-widget-image\" data-id=\"1f5c238\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"625\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-2-1024x625.png\" class=\"attachment-large size-large wp-image-1974\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-2-1024x625.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-2-300x183.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-2-768x469.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/gas-sensing-2.png 1254w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ed43a8e elementor-widget elementor-widget-text-editor\" data-id=\"ed43a8e\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<ul><li><span style=\"box-sizing: inherit; font-weight: bold;\">Infrared sensing<\/span>: Used primarily for CO<span style=\"box-sizing: inherit; font-size: 14.4px; line-height: 1em; position: relative; vertical-align: baseline; bottom: -0.25em; margin-left: 0.078125em;\">2<\/span>\u00a0sensing, a beam of infrared light is passed through a chamber holding the gas of interest. The wavelength is selected to be absorbed by the target gas, therefore the output intensity is proportional to the concentration of gas in the measurement chamber. The nondispersive IR method uses this technique.<\/li><\/ul>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-306cccf elementor-widget elementor-widget-heading\" data-id=\"306cccf\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Acoustic Gas Sensing Concept<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5125100 elementor-widget elementor-widget-text-editor\" data-id=\"5125100\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>We propose an acoustic gas sensing concept that can be independent of material, allowing the detection of multiple gas types with one sensor.\u00a0 \u00a0Our sensor technology relies on in-plane resonators and a simple rectangular cavity which are both easier and cheaper to fabricate than the alternatives.\u00a0 Figure 1 shows the proposed concept.\u00a0 Two in-plane resonators, are coupled through the acoustic resonance of the cavity.\u00a0 \u00a0<\/p><p>The speed of sound in each gas can be expressed by <span class=\"wp-katex-eq\" data-display=\"false\"> c_{gas} = \\sqrt{\\frac{\\gamma \\cdot k \\cdot T}{m}} <\/span><\/p><p>where <span class=\"wp-katex-eq\" data-display=\"false\"> \\gamma <\/span> is the adiabatic index, k is Boltzmann&#8217;s constant, T is the temperature in Kelvin, and m is the mass of a single molecule of gas. For most gases <span class=\"wp-katex-eq\" data-display=\"false\"> \\gamma <\/span> has a unique value around 1.4 and can be assumed as a constant. The remaining variables are temperature and the mass of each gas molecule. Temperature effects can be highly suppressed with a separate measurement and calibration step.<\/p><p>Measuring the speed of sound in a compact and small footprint can provide information about the gas content.\u00a0 In addition, gas viscosity can be measured through the damping of the system.\u00a0 The gas selectivity can be improved by utilizing the speed of sound and viscosity.\u00a0 Resonance based measurements provide high SNR.\u00a0 We propose to use the acoustic resonance of a cavity.\u00a0 One in-plane resonator (drive) excites the acoustic resonance of the cavity, and another in-plane resonator detects the cavity resonance.\u00a0\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-880c4dd elementor-widget elementor-widget-image\" data-id=\"880c4dd\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"853\" height=\"434\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/acoustic-gas-sensing.png\" class=\"attachment-large size-large wp-image-1957\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/acoustic-gas-sensing.png 853w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/acoustic-gas-sensing-300x153.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/acoustic-gas-sensing-768x391.png 768w\" sizes=\"(max-width: 853px) 100vw, 853px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 1: Proposed gas sensor concept, in-plane MEMS resonators are coupled through the acoustic resonance of the cavity. <\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7e8f974 elementor-widget elementor-widget-text-editor\" data-id=\"7e8f974\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>The acoustic resonance frequency of the cavity depends on <span class=\"wp-katex-eq\" data-display=\"false\"> c_{gas} <\/span> and cavity dimensions:&nbsp;<\/p>\n<span class=\"wp-katex-eq\" data-display=\"false\"> f_{lmn}=\\frac{c_{gas}}{2}\\sqrt{(l\/L_X)^2 + (m\/L_Y)^2 + (n\/L_Z)^2}<\/span>\n<p>where l,m,n are nonnegative integers.&nbsp; The cavity has multiple harmonics, we focus on&nbsp; <span class=\"wp-katex-eq\" data-display=\"false\"> f_{100}<\/span> to show the proof of concept.&nbsp; The goal is to match the resonance frequency of drive and sense resonators to the fundamental cavity acoustic resonance.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cb21647 elementor-widget elementor-widget-spacer\" data-id=\"cb21647\" data-element_type=\"widget\" data-widget_type=\"spacer.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-spacer\">\n\t\t\t<div class=\"elementor-spacer-inner\"><\/div>\n\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e19a52a elementor-widget elementor-widget-heading\" data-id=\"e19a52a\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Device description<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-60b0fa9 elementor-widget elementor-widget-text-editor\" data-id=\"60b0fa9\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>Assuming a cavity with <span class=\"wp-katex-eq\" data-display=\"false\"> L_{X}<\/span>=5mm and <span class=\"wp-katex-eq\" data-display=\"false\"> c_{gas}<\/span>=340 m\/s,\u00a0 <span class=\"wp-katex-eq\" data-display=\"false\"> f_{100}<\/span>=34kHz.\u00a0 We designed long and narrow resonators to excite and sense the acoustic resonance while minimally disturbing the cavity acoustics.\u00a0 Figure 2 shows the mode shape of the device.\u00a0 Given the fabrication tolerances, frequency tuning is required for the in-plane resonators.\u00a0 We located 3 drive and 3 sense resonators spanning a total of ~6kHz, each resonator spans ~2kHz.\u00a0 Figure 3 summarizes the overall device structure.\u00a0 We have 6 resonators in the cavity to make sure we can match the acoustic cavity resonance.\u00a0 Figure 4 shows the SEM image of a fabricated device, only 3 resonators are shown in the image.\u00a0\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-4da4ed6 elementor-widget__width-auto elementor-widget elementor-widget-image\" data-id=\"4da4ed6\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"409\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7-1024x409.png\" class=\"attachment-large size-large wp-image-2079\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7-1024x409.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7-300x120.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7-768x307.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7-1536x614.png 1536w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/comsol7.png 1768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 2: FEM analysis showing the mode shape of the device<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-6b6274e e-con-boxed e-flex e-con\" data-id=\"6b6274e\" data-element_type=\"container\" data-settings=\"{&quot;content_width&quot;:&quot;boxed&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7e5ce46 elementor-widget elementor-widget-image\" data-id=\"7e5ce46\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"480\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/drawing-1024x480.png\" class=\"attachment-large size-large wp-image-2082\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/drawing-1024x480.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/drawing-300x140.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/drawing-768x360.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/drawing.png 1119w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 3: Picture summarizing the overall device structure<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-730546c elementor-widget elementor-widget-image\" data-id=\"730546c\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"944\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001-1024x944.png\" class=\"attachment-large size-large wp-image-2080\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001-1024x944.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001-300x276.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001-768x708.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001-1536x1415.png 1536w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/04\/sem_001.png 2048w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 4: SEM image of the fabricated device, 3 resonators shown.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3839cf3 elementor-widget elementor-widget-text-editor\" data-id=\"3839cf3\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>The devices are fabricated with an in-house SOI-MEMS process at Bilkent UNAM.\u00a0 The device, oxide, and handle layer thicknesses are 15 <span class=\"wp-katex-eq\" data-display=\"false\">\\mathrm{\\mu m}<\/span>,\u00a0 2 <span class=\"wp-katex-eq\" data-display=\"false\">\\mathrm{\\mu m}<\/span>, and 600 <span class=\"wp-katex-eq\" data-display=\"false\">\\mathrm{\\mu m}<\/span> respectively.\u00a0 The device layer is highly conductive &lt;100&gt; Silicon.<\/p><ul><li>Cr\/Au is deposited and patterned with wet etch for wirebonding pads.<\/li><li>The device layer is formed with DRIE where SOI oxide acts as an etch-stop layer<\/li><li>The devices are released in buffered HF<\/li><li>The released dies are dried in a critical point dryer (CPD<\/li><\/ul><p>\u00a0<\/p><p>We excite the acoustic resonance with an in-plane resonator.\u00a0 High displacement of the MEMS resonator would result in stronger acoustic cavity resonance and better gas sensitivity.\u00a0 At the same time, the MEMS resonator should match the cavity resonance, which cannot be electrically tuned.\u00a0 Parallel plate capacitors can tune the MEMS resonator frequency but become highly nonlinear at high displacements.\u00a0 We designed length tapered frequency tuning combs that are fundamentally linear.\u00a0 Figure 5 summarizes the concept.\u00a0 As the fingers engage, the rate of capacitance change (dC\/dx) increases linearly.\u00a0 dC\/dx acts as an electrostatic spring that softens the mechanical spring of the MEMS resonator.\u00a0 Unlike parallel plate capacitors, length tapered combs do not suffer from nonlinearity as the displacement increases.\u00a0 They have practically unlimited displacement.\u00a0 We designed the lenght tapered combs for 10\u00a0<span style=\"text-align: start;\"><span class=\"wp-katex-eq\" data-display=\"false\">mathrm{mu m}<\/span><\/span><span style=\"font-style: inherit; font-weight: inherit;\">\u00a0displacement.<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-351d19f elementor-widget elementor-widget-image\" data-id=\"351d19f\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"335\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning-1024x335.png\" class=\"attachment-large size-large wp-image-2192\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning-1024x335.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning-300x98.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning-768x252.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning-1536x503.png 1536w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning.png 1795w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 5: Length tapered frequency tuning combs, as fingers engage the rate of capacitance change (dC\/dx) increases linearly.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c52b7ba elementor-widget elementor-widget-heading\" data-id=\"c52b7ba\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Experimental Results<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8affa44 elementor-widget elementor-widget-text-editor\" data-id=\"8affa44\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>We will first report the performance of the length tapered frequency tuning combs.\u00a0 Figure 6 presents the optical image of the frequency tuning combs and the test configuration.\u00a0 Proof mass voltage (V<sub>PM<\/sub>) of 60V is applied to the movable mass and tuning voltage (V<sub>1<\/sub>) is applied to the stators.\u00a0 Figure 7 shows the tuning curves for the drive and sense resonators.\u00a0 We picked resonator 3 and 5 as the sense and drive resonators, respectively.\u00a0 Going negative for V<sub>1<\/sub> maximizes the tuning range.\u00a0 2kHz tuning range is obtained for the drive and sense resonators.\u00a0 The frequency tuning is directly related with V<sup>2<\/sup><sub>tune<\/sub>.\u00a0 We also measured the speed of sound (<span class=\"wp-katex-eq\" data-display=\"false\"> c_{gas} <\/span>)\u00a0as 343m\/s with an Arduino bases setup and commercially available ultrasonic sensors at room temperature.\u00a0 So we picked a cavity size with <span class=\"wp-katex-eq\" data-display=\"false\"> L_{X}<\/span>=4.8mm that results in <span class=\"wp-katex-eq\" data-display=\"false\"> f_{100}<\/span>=35.7kHz that is within the runing range of the drive and sense resonators.\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-38c104e elementor-widget elementor-widget-image\" data-id=\"38c104e\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"288\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning_with-data-1024x288.png\" class=\"attachment-large size-large wp-image-2203\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning_with-data-1024x288.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning_with-data-300x85.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning_with-data-768x216.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/frequency-tuning_with-data.png 1523w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 6: Test configuration for the frequency tuning combs.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-8d7bf47 elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"8d7bf47\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"614\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/tuning_curve-1024x614.png\" class=\"attachment-large size-large wp-image-2213\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/tuning_curve-1024x614.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/tuning_curve-300x180.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/tuning_curve-768x461.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/tuning_curve.png 1159w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 7: Tuning curves for the drive and sense resonators.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-942dfe4 elementor-widget elementor-widget-text-editor\" data-id=\"942dfe4\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>We carried our experiments with frequency sweeps with and without the cap to demonstrate the acoustic coupling between the drive and sense resonators.\u00a0 Figure 8 shows the test PCB, MEMS device with the Silicon cap and a cartoon summarizing the test conditions.\u00a0 The MEMS device is mounted to a 44-pin ceramic LCC (leadless chip carrier) which is then soldered to a duaghter board.\u00a0 The daughter board is connected to the main PCB housing the electronics.\u00a0 The silicon cap on the MEMS sensor is glued with epoxy, and electrically isolated with a layer of photoresist.\u00a0 As shown in Figure 1 there are three resonators in the proposed system, i.e. drive, sense, and the acoustic cavity.\u00a0 We can electrically tune the frequency of drive and sense resonators.\u00a0 We automated out setup such that it systematically tunes the drive and sense resonators and records the frequency sweep.\u00a0<\/p><p>\u00a0<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-23a20c7 elementor-widget elementor-widget-image\" data-id=\"23a20c7\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"443\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor-1024x443.png\" class=\"attachment-large size-large wp-image-2226\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor-1024x443.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor-300x130.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor-768x332.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor-1536x664.png 1536w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/setup-and-sensor.png 1788w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 8: The test PCB, MEMS device with the Silicon cap, and a cartoon summarizing the operation.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c69408e elementor-widget elementor-widget-text-editor\" data-id=\"c69408e\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>We ran our experiments by only driving the drive resonator and recording the frequency response of the drive and sense resonators for various tuning voltages on the drive and sense resonators.\u00a0 Without the cap on the MEMS die, we do not expect to see significant coupling from the drive to sense resonator.\u00a0 We expect to see drive to sense coupling with the cap through cavity acoustic resonance when the frequencies of the drive, sense and cavity resonance match.\u00a0 Figure 9 and 10 show the sense magnitude, phase and drive magnitude w.r.t. frequency without and with cap on the MEMS die, respectively.\u00a0 Only drive resonator is driven that exhibits a strong response.\u00a0 The sense resonator does not show any significant coupling without the cap, only the response at the maximal coupling (V<sub>td<\/sub>: Drive freq. tuning voltage and V<sub>ts<\/sub>: sense freq. tuning voltage) is plotted.<\/p><p>\u00a0<\/p><p>With the cap on the MEMS die a clear sense response is observed (Figure 10).\u00a0 \u00a0In each row drive frequency is constant and the sense frequency is swept.\u00a0 The sense response peaks and then reduces as it is detuned.\u00a0 Since the acoustic cavity will exhibit second-order response the maximal drive to sense coupling occurs when the three frequencies\u00a0 (drive, sense, and acoustic) match.\u00a0 The acoustic coupling between the drive and sense resonators depends on the gas concentration, and can be employed as a gas sensor with control electronics.<\/p><p><span style=\"font-style: inherit; font-weight: inherit; text-align: var(--text-align);\">\u00a0<\/span><\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-335853a elementor-widget elementor-widget-image\" data-id=\"335853a\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"150\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/uncapped-response-1024x150.png\" class=\"attachment-large size-large wp-image-2295\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/uncapped-response-1024x150.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/uncapped-response-300x44.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/uncapped-response-768x112.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/uncapped-response.png 1123w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 9: Sense magnitude, phase and drive magnitude without the cap on the MEMS die.  Only drive resonator is driven and no significant response is observed on the sense mode.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-dd86865 elementor-widget elementor-widget-image\" data-id=\"dd86865\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"1024\" height=\"416\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/capped-freq-sweeps-1024x416.png\" class=\"attachment-large size-large wp-image-2293\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/capped-freq-sweeps-1024x416.png 1024w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/capped-freq-sweeps-300x122.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/capped-freq-sweeps-768x312.png 768w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/capped-freq-sweeps.png 1274w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 10: Sense magnitude, phase and drive magnitude w.r.t frequency with the cap on the MEMS die.  Only drive resonator is driven, and a clear respose is observed on the sense mode.  Varying the drive and sense resonator frequencies change the coupling proving the acoustic cavity coupling between the resonators.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6447191 elementor-widget elementor-widget-text-editor\" data-id=\"6447191\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>Figure 11 presents a comprehensive look at our experiments with the cap.\u00a0 For each sweep we find the maximum sense voltage and plot it with the corresponding drive and sense resonance frequency.\u00a0 The sense voltage increases towards the diagonal where the drive and sense frequencies are the same, and the maximum occurs ~36kHz, where the cavity acoustic resonance matches the MEMS frequencies.\u00a0 Moving along the diagonal from the 36kHz the sense voltage decreases, proving the acoustic coupling between the drive and sense resonators.\u00a0 The second order cavity acoustic response can be observed along the diagonal in Figure 11.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-5e84d3c elementor-widget__width-initial elementor-widget elementor-widget-image\" data-id=\"5e84d3c\" data-element_type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"921\" height=\"691\" src=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/heatmap.png\" class=\"attachment-large size-large wp-image-2294\" alt=\"\" loading=\"lazy\" srcset=\"https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/heatmap.png 921w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/heatmap-300x225.png 300w, https:\/\/micro.bilkent.edu.tr\/wp-content\/uploads\/2023\/05\/heatmap-768x576.png 768w\" sizes=\"(max-width: 921px) 100vw, 921px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Figure 11: The peak sense amplitude at each frequency sweep.   Sense amplitude increases when the drive and sense frequencies are close.  And when the cavity acoustic frequency matches (~36kHz) maximal coupling occurs proving the acoustic coupling.<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-10f90b1 elementor-widget elementor-widget-heading\" data-id=\"10f90b1\" data-element_type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Summary<\/h2>\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-b8ad911 elementor-widget elementor-widget-text-editor\" data-id=\"b8ad911\" data-element_type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<p>We demonstrated that two in-plane resonators could be coupled through the acoustic resonance of the cavity.\u00a0 The acoustic coupling is an indication of the gas content and along with damping (the rate acoustic resonance vanishes) could be used as a gas sensor.\u00a0 The proof of concept has been shown and future work will focus on building electronics to lock the in-plane resonators to the acoustic cavity resonance and gas tests.\u00a0 The main advantage of the proposed method is its simplicity and it can be used to detect any gas with proper calibration.<\/p>\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Universal Gas Sensing with Acoustic Coupling in a Cavity This project has received funding from the European Union&#8217;s Horizon 2020 research and innovation programme under the Marie Sk\u0142odowska-Curie grant agreement No 101038092. With current gas sensing technologies, sensors have to be developed individually for each gas under test. Most sensors available today rely on one &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"https:\/\/micro.bilkent.edu.tr\/?page_id=1875\"> <span class=\"screen-reader-text\">Research<\/span> Read More &raquo;<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"no-sidebar","site-content-layout":"page-builder","ast-global-header-display":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"disabled","ast-breadcrumbs-content":"","ast-featured-img":"disabled","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","_ti_tpc_template_sync":false,"_ti_tpc_template_id":""},"_links":{"self":[{"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/pages\/1875"}],"collection":[{"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1875"}],"version-history":[{"count":55,"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/pages\/1875\/revisions"}],"predecessor-version":[{"id":2479,"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=\/wp\/v2\/pages\/1875\/revisions\/2479"}],"wp:attachment":[{"href":"https:\/\/micro.bilkent.edu.tr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1875"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}