Development of a wireless power transmission system for guided wave generation and sensing via a laser

Guided waves based nondestructive testing (NDT) techniques have attracted many researchers' attentions for structural health monitoring due to their relative long sensing range. These guided waves in a structure can be generated and sensed by a variety of techniques. This study proposes a new wireless scheme for PZT excitation and sensing, where power as well as measured data can be transmitted via laser. First, a generated waveform modulated by a laser is wirelessly transmitted to a photodiode connected to a PZT on the structures. Then, the photodiode converts the light into an electrical signal and excites the PZT and the structure. The reflected response signal received at the same PZT is reconverted into a laser, which is transmitted back to another photodiode located at the data acquisition unit for diagnosis. The feasibility of the proposed power transmission scheme has been experimentally demonstrated at a laboratory setup. The wireless data transmission aspect is under verification. Since there is no need for a power supply and a signal generator at the PZT transducer node, a self-sufficient PZT transducer unit can be realized with little additional electronic components.