Charge-programmed three-dimensional printing for multi-material electronic devices

Three-dimensional (3D) printing can create complex geometries that could be of use in the development of electronics. However, the approach is mainly limited to non-functional structural materials, and the 3D printing of electronic devices typically requires multiple process stages of embedding, spraying and writing. Here, we report a 3D printing approach that can volumetrically deposit multiple functional materials within arbitrary 3D layouts to create electronic devices in a single step. Our approach prints 3D structures with a programmable mosaic of distinct surface charge regions, creating a platform to deposit functional materials into complex architectures based on localized electrostatic attraction. The technique allows selective volumetric depositions of single metals and also diverse active material combinations, including ceramic, semiconducting, magnetic and colloidal materials, into site-specific 3D topologies. To illustrate the capabilities of our approach, we use it to fabricate devices with 3D electronic interfaces that can be used for tactile sensing, internal wave mapping and shape self-sensing. A 3D printing technique that produces structures with programmable patterns of charged surface, allowing different functional materials to be deposited in pre-defined regions, can be used to create electronic devices with a single printing step.