Tire tread deformation sensor and energy harvester development for smart-tire applications

Pneumatic tires are critical components in mobile systems that are widely used in our lives for passenger and goods transportation. Wheel/ground interactions in these systems play an extremely important role for not only system design and efficiency but also safe operation. However, fully understanding wheel/ground interactions is challenging because of high complexity of such interactions and the lack of in situ sensors. In this paper, we present the development of a tire tread deformation sensor and energy harvester for real-time tire monitoring and control. Polyvinylidene fluoride (PVDF) based micro-sensor is designed and fabricated to embed inside the tire tread and to measure the tread deformation. We also present a cantilever array based energy harvester that takes advantages of the mechanical bandpass filter concept. The harvester design is able to have a natural frequency band that can be used to harvest energy from varying-frequency vibrational sources. The energy harvester is also built using with new single crystal relaxor ferroelectric material (1 - &Vkgr;)Pb(Mg_1/3Nb_2/3)O₃-&Vkgr;PbTiO₃ (PMN-PT) and interdigited (IDT) electrodes that can perform the energy conversion more efficiently. Some preliminary experiment results show that the performance of the sensor and the energy harvester is promising.