Flexible Antenna with Microfluidics for the Quantification of Liquid Micro-Volumes

Microfluidics has been a significant technology for over a decade, particularly in medical and wearable devices. It allows for the manipulation of small amounts of fluid in a confined space and can synergize with auto-tuning microchips that are able to modify their internal capacitance to maximize power delivery to the antenna. Hence, the first prototype of an auto-tuning RFID sensor exploiting a microfluidic channel is designed, manufactured, and tested in this contribution. A small liquid volume of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1050\ μ L</tex> is successfully monitored by the auto-tuning sensor in a continuous way when using <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">155-μ m</tex> - and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">775-μ m-thick</tex> microfluidic. The investigated technology could be used to monitor sweating in pathological conditions according to the point-of-care paradigm or estimate food degradation through smart packaging.