This paper proposes a novel multi-material 3D low-temperature co-fired ceramic base called NeuroStone. It employs 3D inkjet printing with ceramic and copper particle suspension, followed by cofiring. This technology provides both free-form and non-planar electrodes not only on the surface but also inside the device. NeuroStone makes it possible to enhance the directional freedom and electrode packing density in the field of miniature interconnection devices. This report demonstrates that the proposed technology can realize sophisticated shapes of interconnection devices fabricated by additive manufacturing, which can significantly enhance the scope of electronics.INDEX TERMS Additive manufacturing, ceramic device, direct print, printed electronics, three-dimensional electronics, three-dimensional printing.

A major bottleneck in the manufacturing process of a medical implant capable of biopotential measurements is the design and assembly of a conductive electrode interface. This paper presents the use of a novel 3D-printing process to integrate conductive metal surfaces on a low-temperature co-fired ceramic base to be deployed as electrodes for electrocardiography (ECG) implants for small animals. In order to fit the ECG sensing system within the size of an injectable microchip implant, the electronics along with a pin-type lithium-ion battery are inserted into a cylindrical glass tube with both ends sealed by these 3D printed composite electrode discs using biomedical epoxy. In the scope of this paper, we present a proof-of-concept in vivo experiment for recording ECG from an avian animal model under local anesthesia to verify the electrode performance. Simultaneous recording with a commercial device validated the measurements, demonstrating promising accuracy in heart rate and breathing rate monitoring. This novel technology could open avenues for the mass manufacturing of miniaturized ECG implants.Clinical relevance-A novel manufacturing process and an implantable system are presented for continuous physiological monitoring of animals to be used by veterinarians, animal scientists, and biomedical researchers with potential future applications in human health monitoring.