Flexible wireless power transfer module implemented with aerojet-printing and laser-sintering of rigid NiZn-ferrite ceramic films

摘要

Integrating high-performance inorganic ceramic materials into flexible electronics has long been considered a technical challenge because of the conceptual clash between rigidity and flexibility. Moreover, the inevitable high-temperature processing of ceramic materials is incompatible with other materials used in flexible electronics. To address these issues, this work suggests a novel solution to incorporate rigid NiZn-ferrite (NZF) ceramic films into a flexible wireless power transfer (WPT) module via aerojet-printing and laser-sintering processes. The aerojet-printed NZF films exhibited excellent magnetic properties after laser sintering. Although laser sintering induced unexpected microcracks in the NZF films due to the rapid heating of the laser and the high porosity of the printed films, they played an important role in imparting flexibility to the NZF films. The laser-sintered NZF (LSNZF) films were separated from the substrate using an Ag sacrificial layer and then embedded into polydimethylsiloxane (PDMS). The flexibility of the PDMS-embedded LSNZF films was investigated via a bending test. The flexible WPT receiving (Rx) module was completed by combining the PDMS-embedded LSNZF films with an inkjet-printed Ag inductor coil. The performance of the flexible WPT Rx module was verified via wireless activation of light emitting diodes.