Reviewed by Alex SmithDec 1 2022
Scientists from Japan and Singapore have devised a novel 3D printing technology for creating exact patterns on the external and internal surfaces of 3D plastic structures.
Examples of 3D metal–plastic composites that can be prepared by the new technology. Image Credit: Waseda University.
Due to its enormous potential in the fabrication of next-generation electronics, research interest in 3D printing of metal patterns on plastic parts has developed rapidly in recent years. However, producing such intricate pieces using traditional methods is difficult. Scientists from Japan and Singapore have now created a novel 3D printing technology for the creation of complicated 3D metal-plastic composite structures.
Three-dimensional (3D) metal-plastic composite structures offer a broad range of possible applications, including smart electronics, micro/nanosensing, internet-of-things (IoT) devices, and potentially quantum computing. Devices built using these architectures offer a greater degree of design freedom and can have more sophisticated features, complex geometry, and smaller sizes. However, present methods for producing such parts are costly and difficult.
A group of Japanese and Singaporean academics has devised a new multimaterial digital light processing 3D printing (MM-DLP3DP) technology for fabricating metal-plastic composite structures with arbitrarily complicated shapes.
Elaborating on the motivation behind the research, lead authors Professor Shinjiro Umezu, Mr Kewei Song from Waseda University, and Professor Hirotaka Sato from Nanyang Technological University, Singapore stated, “Robots and IoT devices are evolving at a lightning pace. Thus, the technology to manufacture them must evolve as well. Although existing technology can manufacture 3D circuits, stacking flat circuits is still an active area of research. We wanted to address this issue to create highly functional devices to promote the progress and development of human society.”
The research was published in ACS Applied Materials & Interfaces.
The MM-DLP3DP process is a multi-step procedure that begins with the synthesis of active precursors—chemicals that can be transformed into the intended chemical after 3D printing because the desired chemical cannot be 3D printed. To prepare the active precursors, palladium ions are added to light-cured resins.
Image Credit: Pixel B/Shutterstock.com
This is done to encourage electroless plating (ELP), which is the auto-catalytic reduction of metal ions in an aqueous solution to generate a metal coating. The MM-DL3DP apparatus is then utilized to create microstructures with nested sections of the resin or active precursor. Eventually, these materials are directly plated and ELP is used to add 3D metal designs to them.
To illustrate the manufacturing capabilities of the suggested technique, the research group created a variety of parts with complex topologies. These parts featured intricate constructions with multimaterial nesting layers, as well as microporous and microscopic hollow structures, the smallest of which was 40 μm in size.
Furthermore, the metal patterns on these parts were exceedingly unique and accurate. The team also created 3D circuit boards with intricate metal topologies, such as an LED stereo circuit with nickel and a double-sided 3D circuit with copper.
Umezu, Song, and Sato added, “Using the MM-DLP3DP process, arbitrarily complex metal–plastic 3D parts having specific metal patterns can be fabricated. Furthermore, selectively inducing metal deposition using active precursors can provide higher quality metal coatings. Together, these factors can contribute to the development of highly integrated and customizable 3D microelectronics.”
The novel manufacturing process claims to be a major boost in circuit fabrication, with applications in a wide range of technologies such as 3D electronics, metamaterials, flexible wearable devices, and metal hollow electrodes.
Journal Reference:
Song, K., et al. (2022) New Metal–Plastic Hybrid Additive Manufacturing for Precise Fabrication of Arbitrary Metal Patterns on External and Even Internal Surfaces of 3D Plastic Structures. ACS Applied Materials & Interfaces. doi.org/10.1021/acsami.2c10617.