AUTHOR=Nam Juhong , Byun Eunjeong , Shim Hyunji , Kim Esther , Islam Sayemul , Park Moonchul , Kim Albert , Song Seung Hyun 

TITLE=A Hydrogel-Based Ultrasonic Backscattering Wireless Biochemical Sensing

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=8

YEAR=2020

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2020.596370

DOI=10.3389/fbioe.2020.596370

ISSN=2296-4185

ABSTRACT=<p>Wireless monitoring of the physio-biochemical information is becoming increasingly important for healthcare. In this work, we present a proof-of-concept hydrogel-based wireless biochemical sensing scheme utilizing ultrasound. The sensing system utilizes silica-nanoparticle embedded hydrogel deposited on a thin glass substrate, which presents two prominent interfaces for ultrasonic backscattering (tissue/glass and hydrogel/glass). To overcome the effect of the varying acoustic properties of the intervening biological tissues between the sensor and the external transducer, we implemented a differential mode of ultrasonic back-scattering. Here, we demonstrate a wireless pH measurement with a resolution of 0.2 pH level change and a wireless sensing range around 10 cm in a water tank.</p>