Disposable Microwave Sensor for Real-time Monitoring and Content Sensing of Droplets in Microfluidic Devices

A novel chemical sensor with zero power consumption is presented for real-time, non-contact, and noninvasive droplet characterization within the microchannel. The proposed microwave-microfluidic device demonstrates the capability of performing droplet detection as well as sensing of an individual droplet content. The platform is based on a chipless flexible microwave resonator tag coupled to a reader for introducing a technique to reduce the dependency of the coupling to the distance. The performance of the microwave-microfluidic sensor has been validated when mineral oil is used as the continuous phase. The sensor demonstrates highly selective identification results when deionized water and acetone are used to generate droplets required to be detected.