Piezoelectric-pneumatic material jetting printing for non-contact conformal fabrication of high-temperature thick-film sensors

Conformal printing of high -temperature thick -film sensors (TFSs) on intricate surfaces is crucial for precise integration and enhanced functionality. However, traditional contact printing faces challenges in terms of the complex motion control of 3D surfaces. With the core concept of non -contact printing, this study employs piezoelectric -pneumatic material jetting (PPMJ) to achieve rapid and uniform manufacturing of complex and multi -material conformal TFSs. PPMJ enables a wide viscosity range (50-100,000 mPa.s) and high solid content (60 wt%), accommodating various types of inks, from insulating to semiconductor materials to high -temperature alloy slurries, thus providing a broad operational window for shape control and performance modulation in the conformal manufacturing of TFSs on curved surfaces. Microscale shape control of ceramic ink features, including a parallel three-phase contact line, uniform print dimensions, and post -curing shape control, was systematically investigated. PPMJ printing facilitates the successful in situ fabrication of multi -layer TFSs, featuring the selfassembly of droplets and dependable printing consistency, with nozzle -to -substrate heights ranging from 1 to 10 mm, thus advancing the structural arrangement, design, and manufacturing of conformal multi -layer TFSs on curved surfaces. For example, the polymer -derived ceramic heat flux sensor printed by PPMJ demonstrates repeatable high -temperature responsiveness and can be integrated on the surface of turbine blades, withstanding thermal impacts from flames exceeding 800 C. Hence, PPMJ printing technology opens new possibilities for the conformal manufacturing of various sensors on complex 3D surfaces.