A Batteryless, Wireless Strain Sensor Using Resonant Frequency Modulation.

Kyeong Lee,Namsun Chou,Sohee Kim

doi:10.3390/s18113955

Abstract

In this study, we demonstrated the feasibility of a wireless strain sensor using resonant frequency modulation through tensile impedance test and wireless sensing test. To achieve a high stretchability, the sensor was fabricated by embedding a copper wire with high conductivity in a silicone rubber with high stretchability, in which the resonant frequency can be modulated according to changes in strain. The characteristics of the sensor and the behavior of wireless sensing were calculated based on equations and simulated using finite element method. As the strain of the sensor increased, the inductance increased, resulting in the modulation of resonant frequency. In experimental measurement, as the strain of the sensor increased from 0% to 110%, its inductance was increased from 192 nH to 220 nH, changed by 14.5%, and the resonant frequency was shifted from 13.56 MHz to 12.72 MHz, decreased by 6.2%. It was demonstrated that using the proposed sensor, strains up to 110% could be detected wirelessly up to a few centimeters.

Highlights

Stomach cancer is one of the common cancers in Northeast Asian male population [1,2].The general treatment is gastrectomy, which removes the stomach or the small intestine partially or totally [3,4,5]
In case of EGG, the electrodes must be attached onto the operated skin of the patient [9]
As a potential alternative to those methods, we propose a sensor that can be attached to the stomach directly and detect the stomach deformation wirelessly

Summary

Introduction

Stomach cancer is one of the common cancers in Northeast Asian male population [1,2].The general treatment is gastrectomy, which removes the stomach or the small intestine partially or totally [3,4,5]. The stomach motility is observed to check normal gastric emptying functions using several clinical methods such as gastric emptying time measurement, ultrasound, scintigraphy, and gastroscopy [6,7,8]. Methods such as electrogastrography (EGG) and magnetogastrography (MGG) have been introduced to quantitatively measure the stomach motility. In case of EGG, the electrodes must be attached onto the operated skin of the patient [9]. In case of MGG, it can be measured only in the place where the huge facility such as Superconducting

Methods

Results

Conclusion