Self-Powered MEMS Sensors for Advanced Turbine Disk/Blade PHM Systems

Previous instrumentation for real-time aircraft turbine blade/disk PHM includes non-intrusive optical, eddy current, and capacitive-based probes as well as blade-mounted transducers for direct measurement of blade condition. Noncontact optical probes have demonstrated higher accuracy than competing eddy current and capacitive-based probes, but are prone to contamination from debris. Fueled by the overwhelming need for NDE sensors for an advanced turbine blade PHM system, Lambda Instruments, Inc.proposes to investigate the feasibility of using self-powered MEMS sensors directly attached to turbine blades for real-time monitoring of blade vibration, temperature, and strain. The salient features of the proposed MEMS sensors include 1) extremely low power, opening the possibility of self-powering using energy harvesting techniques, 2) high sensitivity and resolution using optical interferometry, 3) low-profile geometry allowing sensors to be installed between blade/disk surface and thermal barrier coating (TBC), 4) no slip rings – sensor output will be wirelessly transmitted to remote PHM system computer, and 5) the proposed sapphire optical fiber-based MEMS sensors can operate up to 3600º F, the melting point of single-crystal sapphire.