The concept of sensing environmental parameters in the air has been raised recently by utilizing drone-based, insect-based, or wind-dispersal-based mechanisms using different system infrastructures. Interestingly, wind-dispersal mechanisms use no driving mechanical system and can be dispersed only by the wind power to scan and sense selected areas of interest. Additionally, Ultra High Frequency (UHF) passive Radio Frequency IDentification (RFID) technology is considered with a low-cost infrastructure and high coding capacity of 96 bits in which RFID tags operate without the need for a battery. In this paper, we propose a system of wind-dispersal fliers which are coded and localized based on passive UHF RFID technology toward sensing environmental parameters (e.g. temperature) at a specific position in space. For the flier’s mechanical design, a 2D structure is first designed, inspired by winged seeds, that consists of four wings with asymmetrical cross-sections between them in order to provide better mechanical stability during descent and more integration solutions with UHF RFID tags. The 2D structure is then transformed into 3D configurations by tilting the blades at different angles and utilizing different curvatures. By introducing porosity in the 3D design and optimizing the blades’ angles and curvature, a low terminal velocity of 1.64 m/s is achieved based on measurements. The fliers are fabricated using Laser Sintering from Polyamide 12 (PA12) which has a low weight and good mechanical properties with a low thickness of 200 μm. For system demonstration toward reliable identification, localization, and tracking of fliers during falling, distributed reader antennas are used to interrogate a coded flier equipped with a passive RFID tag that uses a UHF Gen2 chip. Received Signal Strength Indicator (RSSI) based localization is used with an adaptive trilateration algorithm to tackle environmental impairments. The averaged measured location error achieved based on the proposed system is approximately 8.5 cm.
