Autoclave Reliability of MEMS Pressure and Temperature Sensors Embedded in Carbon Fiber Composites

In this paper, embedding of surface mount pressure and temperature sensors in the carbon fiber composites are described. Commercially available surface mount pressure and temperature sensors are used for embedding in a composite lay-up of IM6/HST-7, IM6/3501, and AS4/E7T1-2 prepregs. The fabrication techniques developed here are the focus of this paper. A successful embedding procedure of pressure and temperature sensors in fibrous composites is described in detail. The description includes techniques for positioning and insulating the sensors and the lead wires from the conductive carbon prepregs. Procedural techniques are developed and discussed for isolating the pressure sensor’s flow-opening, from the exposure to the prepreg epoxy flow and exposure to the fibrous particles, during the autoclave curing of the composite laminate. The effects of the autoclave cycle (if any) on the operation of the embedded pressure and temperature sensors are discussed.