Many products critical to modern society, including pharmaceuticals and food, must be processed, stored, and shipped in a constantly refrigerated environment. Current methods to measure temperature are poorly suited for the high-volume and real-time measurements that are needed to monitor this cold chain. This collaborative project aims to provide the basis for new low-cost battery-free temperature sensing systems that can be integrated into radio-frequency identification (RFID) packaging. This project advances national health and welfare priorities by providing the fundamental knowledge for a smart antenna sensing technology that will enable next-generation low-cost packaging for safe transportation of food and medicine. This will enhance national capabilities for disease prevention (e.g., reducing foodborne illness) and treatment (e.g., ensuring effective vaccinations). This work is also expected to enable new sensing systems in agriculture and pharmaceutical manufacturing. This project will be carried out by a multidisciplinary team with complementary expertise in electromagnetic systems and smart materials at the Florida International University and the University of Texas at Dallas, respectively. The results of this research will be broadly disseminated to both the academic community and industrial community through conferences, seminars, and publications. This project also supports educational efforts that are focused on broadening participation of underrepresented groups in STEM through curriculum development, undergraduate research programs, and community outreach efforts designed to impact K-12 students. The proposed sensing systems will be based on self-reconfiguring antennas that, in response to a change in temperature, undergo controllable and reversible changes in shape. This change in shape will be harnessed to alter antenna performance and enable continuous, passive, and accurate RFID temperature sensing. Shape change will be driven by active polymeric substrates that can be programmed to undergo bending, twisting, or folding. These materials will be synthesized by programming the molecular order, and therefore the type of shape change, in temperature-responsive liquid crystal elastomers (LCEs). This project promotes scientific advancement by addressing the fundamental materials and electromagnetic design challenges necessary to create shape-changing antennas that also change their measurable properties over the broad temperature range of interest. Specifically, this work aims to: 1) synthesize new LCE materials that reversibly change shape in response to temperatures between -80°C and 50°C, 2) design processes to pattern electronic materials including conductive antenna traces on LCE substrates, and 3) design and characterize reversibly self-morphing LCE antennas that can dynamically reconfigure their electromagnetic performance in response to temperature change. This research is expected to lead to significant advances in sensors and enable new examples of morphing electronics including antenna arrays and frequency selective surfaces.
