Resonant surface acoustic wave chemical detector
| DWPI Title: Apparatus for chemical detection, has interdigitated transducers comprising mutually facing edges, where adsorptive layer covers velocity-correcting fingers and extends from mutually facing edge to another mutually facing edge |
| Abstract: Apparatus for chemical detection includes a pair of interdigitated transducers (IDTs) formed on a piezoelectric substrate. The apparatus includes a layer of adsorptive material deposited on a surface of the piezoelectric substrate between the IDTs, where each IDT is conformed, and is dimensioned in relation to an operating frequency and an acoustic velocity of the piezoelectric substrate, so as to function as a single-phase uni-directional transducer (SPUDT) at the operating frequency. Additionally, the apparatus includes the pair of IDTs is spaced apart along a propagation axis and mutually aligned relative to said propagation axis so as to define an acoustic cavity that is resonant to surface acoustic waves (SAWs) at the operating frequency, where a distance between each IDT of the pair of IDTs ranges from 100 wavelength of the operating frequency to 400 wavelength of the operating frequency. |
| Use: Apparatus for chemical detection. |
| Advantage: The apparatus potentially increases sensitivity of a detector by increasing effective number of passes of an acoustic wave through a detection zone in which analyte is present. The apparatus suppresses undesired acoustic reflections from acoustic impedance discontinuities in a propagation path. The apparatus maintains target impedance in design by reducing an aperture size, while compensating by adding more finger pairs. |
| Novelty: The apparatus has interdigitated transducers (IDT) fingers and velocity-correcting fingers for collectively forming single periodic pattern in which continuity of mass loads due to the IDT fingers are continued across a piezoelectric substrate (400), where each IDT is conformed as a floating electrode uni-directional transducer (FEUDT). The IDTs comprise mutually facing edges, and an adsorptive layer covers the velocity-correcting fingers and extends from the mutually facing edge to another mutually facing edge without encroaching on either of the IDTs. |
| Filed: 4/3/2014 |
| Application Number: US14244767A |
| Tech ID: SD 12244.1 |
| This invention was made with Government support under Contract No. DE-NA0003525 awarded by the United States Department of Energy/National Nuclear Security Administration. The Government has certain rights in the invention. |
| Data from Derwent World Patents Index, provided by Clarivate All rights reserved. Republication or redistribution of Clarivate content, including by framing or similar means, is prohibited without the prior written consent of Clarivate. Clarivate and its logo, as well as all other trademarks used herein are trademarks of their respective owners and used under license. |