Sustainable Printed Chitosan-Based Humidity Sensor on Flexible Biocompatible Polymer Substrate

Printed RFID Humidity Sensor Tags for Flexible Smart Systems

Radio frequency identification (RFID) and sensing are two key technologies enabling the Internet of Things (IoT). Development of RFID tags augmented with sensing capabilities (RFID sensor tags) would allow a variety of new applications, leading to a new paradigm of the IoT. Chipless RFID sensor technology offers a low-cost solution by eliminating the need of an integrated circuit (IC) chip, and...

Silver nanoparticle polymer composite based humidity sensor.

Silver nanoparticles were synthesised by a chemical reduction process in order to produce an aqueous colloidal dispersion. The resulting colloids were then characterised by a combination of UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction and transmission electron microscopy and the nanoparticles were found to have an average diameter of 20-22 nm. The Ag/polymer nanocomposites w...

An all-printed wireless humidity sensor label

Diode-switched thermal-transfer printed antenna on flexible substrate

We demonstrate that diode-switching can be used to introduce frequency agility into antennas produced by thermal transfer printing. Our particular example is a triangular Sierpinski fractal pattern with two PIN diodes to switch between operation optimised for the 800 MHz UHF band (diodes on) and the 2400 MHz ISM band (diodes off). Our measured results show an improvement in S11 in the UHF band ...

Compact optical curvature sensor with a flexible microdisk laser on a polymer substrate.

We demonstrate a chip-scale compact optical curvature sensor. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. ...