Battery-Free Shape Memory Alloy Antennas for Detection and Recording of Peak Temperature Activity

Abstract

Economical sensing and recording of temperatures are important for monitoring the supply chain. Existing approaches measure the entire temperature profile over time using electronic devices running on a battery. This paper presents a simple, intelligent, battery-free solution for capturing key temperature events using the natural thermo-mechanical state of a Shape Memory Alloy (SMA). This approach utilizes the temperature-induced irreversible mechanical deformation of the SMA as a natural way to capture the temperature history without the need for electronic data logging. In this article, two-way SMA is used to record both high-temperature and low-temperature peak events. Precise thermo-mechanically trained SMA are employed as arms of the dipole antenna for Radio Frequency (RF) readout. The fabricated antenna sensor works at 1 GHz and achieves a sensitivity of 0.24 dB/°C and −0.16 dB/°C for recording temperature maxima and minima, respectively.

Editorial: Application of Shape Memory Alloys

“…Conventional methods involve using electronic devices powered by batteries to measure and record temperature profiles over time. Wang and colleagues [5] introduce a cost-effective and intelligent battery-free solution for capturing crucial temperature events by leveraging the inherent thermo-mechanical properties of a shape memory alloy (SMA). The proposed approach takes advantage of the SMA's temperature-induced irreversible mechanical deformation as a natural means of capturing temperature history, eliminating the need for electronic data logging.…”

A Feasibility Study on Monitoring Earthquake-Caused Furniture Vibrations Using Radiofrequency Identification Sensor Tags

“…The RFID reader radiates radio waves toward the RFID tags, and the RFID tags subsequently return unique electronic product codes (EPCs) to the RFID reader. RFID sensor tags have recently emerged, and they also measure the temperatures [ 20 , 21 , 22 ], humidity [ 23 ], human activity [ 24 , 25 ], vibrations [ 26 ], physical shocks [ 27 ], and pressures of the surrounding environments [ 28 ]. With these sensing capabilities, RFID systems can function as wireless IoT devices [ 29 , 30 , 31 , 32 , 33 ].…”

Tunable Radio Frequency Antenna Based on Phase Change Materials

“…SMAs can achieve reconfigurable shapes by varying the temperature applied to the antenna. This phase changing memory behavior has been utilized in wireless temperature sensors where the antenna shape can record the temperature extrema. − In this article, a new approach is proposed for antenna reconfiguration through thermal programming of the underlying SMA rather than dedicated circuit elements. Temperature change causes the shape of the antenna to change in order to tune the input impedance of the antenna.…”