Direct Measurement of Bondline Temperature During Composite Repair/Fabrication

ABSTRACT: METSS will design and fabricate a battery-free wireless sensor to monitor the temperature of the bondline region during the vacuum curing of a composite material on the damaged region of an aircraft.The sensor will be designed for placement directly into the region to monitor and transmit a signal to a reader outside of the vacuum bag.The sensor, smaller than the pre-determined critical flaw size, will include a thin film epoxy substrate, chemically etched copper antenna, and semiconductor based temperature sensing material.METSS will formulate a novel substrate material that directly incorporates itself into the composite matrix, reducing any loss of mechanical properties.The copper antenna, an electric-inductive-capacitive resonator, will interact with the electromagnetic waves broadcast from the reader and generate a corresponding temperature based signal due to the electrical response of the metal oxide sensing material.METSS will measure the sensor response with techniques similar to those found in the commercial sector of radio frequency identification (RFID) tags.; BENEFIT: METSSs work with the sensor development will parallel collaboration in the commercial sector to adapt the current hot bonders used in the field for the vacuum bagging technology.The target is to develop a sensor platform that can be directly incorporated into the current temperature control system, minimizing the time from lab-bench to the flight line.Further development of the technology will result from the design and manufacture of a low cost handheld reader for the sensor.METSS will utilize commercial partnerships to transition the sensor platform into industry displacing a segment of wireless temperature monitoring.