Collaborative Research: Passive RFID Real-Time Temperature-Sensing Based on Programmable Liquid Crystal Elastomers

许多对现代社会至关重要的产品，包括药品和食品，必须在持续冷藏的环境中加工、储存和运输。目前测量温度的方法不适合监测冷链所需的大容量和实时测量。该合作项目旨在为新的低成本无电池温度传感系统提供基础，该系统可集成到射频识别（RFID）包装中。该项目通过提供智能天线传感技术的基础知识来推进国家健康和福利优先事项，该技术将使下一代低成本包装能够安全运输食品和药品。这将增强国家预防疾病的能力（例如，减少食源性疾病）和治疗（例如，确保有效的疫苗接种）。这项工作也有望在农业和制药业中实现新的传感系统。该项目将由一个多学科小组进行，该小组分别在佛罗里达国际大学和德克萨斯大学达拉斯分校拥有电磁系统和智能材料方面的互补专业知识。这项研究的结果将通过会议、研讨会和出版物向学术界和工业界广泛传播。该项目还支持教育工作，重点是通过课程开发，本科研究计划和旨在影响K-12学生的社区外展工作，扩大代表性不足的群体在STEM中的参与。所提出的传感系统将基于自重构天线，该天线响应于温度的变化，在形状上经历可控和可逆的变化。这种形状的变化将被用来改变天线性能，并实现连续、无源和准确的RFID温度传感。形状变化将由活性聚合物基底驱动，所述活性聚合物基底可被编程以经历弯曲、扭曲或折叠。这些材料将通过编程分子顺序来合成，因此在温度响应性液晶弹性体（LCE）中的形状变化类型。该项目通过解决基础材料和电磁设计挑战来促进科学进步，这些挑战是创建形状变化天线所必需的，这些天线也会在广泛的温度范围内改变其可测量特性。具体来说，这项工作的目的是：1）合成新的LCE材料，响应于-80 ° C和50°C之间的温度可逆地改变形状，2）设计工艺来图案化电子材料，包括LCE基板上的导电天线迹线，以及3）设计和表征可逆自变形LCE天线，可以动态地重新配置其电磁性能，以响应温度变化。这项研究预计将导致传感器的重大进展，并使变形电子产品的新例子，包括天线阵列和频率选择表面。

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.