Wireless and batteryless vibration testing of space structures with implanted LSI sensors

Vibration testing and modal survey of space structures usually afflict labour intensive and delicate sensor attachments and power/signal wire routings not to damage delicate space structures. In this paper, we propose to implant tiny wireless and batteryless sensors to space structures at the time of fabrication to eradicate the power/signal wiring burden for their entire structural lifecycle by providing power to the implanted sensors with radio wave. The vibration data is concurrently collected from multiple sensors as the reflection of radio wave. The mutually interfering reflections are processed in an interrogator to separate the signals to produce a transition matrix. The concurrent and synchronized collection of sensor data is realized by a newly invented wireless access method tailored to low functional sensors, referred to as Multiple Subcarrier Multiple Access (MSMA). In this paper, we outline the theory and challenges of MSMA and report the state of art of the development with experimental results.