ABSTRACT
With the current development of the 5G infrastructure, there presents a unique opportunity for the deployment of battery-less mmWave reflect-array-based sensors. These fully-passive devices benefit from having a larger detectability than alternative battery-less solutions to create self-monitoring megastructures. The presented 'smart' skin sensor uses a Van-Atta array design enabling ubiquitous local strain monitoring for the structural health monitoring of composite materials featuring wide interrogation angles. Proof-of-concept prototypes of these 'smart' skin millimeter-wave identification tags, that can be mounted on or embedded within common materials used in wind turbine blades, present a highly-detectable radar cross-section of - 33.75 dBsm and - 35.00 dBsm for mounted and embedded sensors respectively. Both sensors display a minimum resolution of 202 µ -strain even at 40 ∘ off-axis enabling interrogation of the fully-passive sensor at oblique angles of incidence. When interrogated from a proof-of-concept reader, the fully-passive, sticker-like mmID enables local strain monitoring of both carbon fiber and glass fiber composite materials. The sensors display a repeatable and recoverable response over 0-3000 µ -strain and a sensitivity of 7.55 kHz/ µ -strain and 7.92 kHz/ µ -strain for mounted and embedded sensors, respectively. Thus, the presented 5G-enabled battery-less sensor presents massive potential for the development of ubiquitous Digital Twinning of composite materials in future smart cities architectures.
ABSTRACT
Multiple designs of textile-based sensors were developed and integrated into blankets for the measurement of Electrocardiogram (ECG) signals. Once the patient makes direct skin contact with the electrodes, the ECG signals are acquired and transmitted wirelessly by a wireless data acquisition unit to an associated computer for analysis, assessment and storage. A variety of designs and manufacturing methods were tested. An adult human subjects' study was conducted to test the feasibility of these measurements as well as to test the different design types and manufacturing methods. The heart rate and Signal to Noise ratio (SNR) are comparable to the gold standard adhesive lead measurements.
