Tunable Chipless RFID Pressure Sensor Utilizing Additive Manufacturing

Each sensing application has its own set of unique requirements and constraints that must be satisfied by the sensor. These requirements can include being wireless, passive, non-contact, customizable, multi-functional, and/or minimally invasive, depending on the application. Chipless RFID tags are a type of microwave sensor that have the potential to meet many of these requirements, especially when additive manufacturing (AM) is employed to create customizable substrates that are sensitive to different ranges of environmental measurands. This work examines the efficacy of a proposed chipless RFID pressure sensor that utilizes an AM substrate. Complex permittivity and stress-strain measurements were conducted to develop a model that relates the resonant frequency of the chipless RFID sensor to pressure, which in turn allows for the design of pressure sensors with customized sensing ranges and sensitivities. Simulations and measurements of a fabricated tag were conducted to provide a proof-of-concept of the developed model and sensor design approach.