Planar-type resistance temperature detectors (P-RTDs) were fabricated via fused deposition modeling by dual nozzle extrusion. The temperature-sensing element of the fabricated sensor was printed with electrically conductive polylactic acid/carbon black (PLA/CB) composite, while the structural support was printed with a PLA insulator. The temperature-dependent resistivity change of PLA/CB was evaluated for different stacking sequences of PLA/CB layers printed with [0°/0°], [−45°/45°], and [0°/90°] plies. Compared to a PLA/CB filament used as 3D printing source material, the laminated structures exhibited a response over 3 times higher, showing a resistivity change from −10 to 40 Ω∙cm between −15 and 50 °C. Then, using the [0°/90°] plies stacking sequence, a P-RTD thermometer was fabricated in conjunction with a Wheatstone bridge circuit for temperature readouts. The P-RTD yielded a temperature coefficient of resistance of 6.62 %/°C with high stability over repeated cycles. Fabrication scalability was demonstrated by realizing a 3 × 3 array of P-RTDs, allowing the temperature profile detection of the surface in contact with heat sources.

The evaluation of temperature variation is very important issue relations in the fields of mechanical design, maintenance and advanced material. Development of carbon fiber or variable composites material is increasingly used in novel material especially aerospace field. One of the key factors in developing novel materials is finding alternative sources of power. Recent research trend is to develop self-actuating device from natural source. The main example is shape memory alloys(SMA), shape memory polymer(SMP) and etc. To develop the SMA or SMP, Thermal properties of material are important. Then the use of nondestructive testing(NDT) techniques is useful to get thermal data about novel materials. Infrared thermography(IRT) is convenient and useful method of NDT technique. However, IRT require various variables to get a proper data. In this research, we trying to reduce the number and find the emissivity of variables on bimaterial from 3D printing.