NUS develops technology to fabricate 3D circuits for advanced electronics

CHARM3D allows efficient printing of free-standing 3D structures.

A team of researchers from the National University of Singapore (NUS) has introduced a new technique called CHARM3D that fabricates three-dimensional (3D), self-healing electronic circuits, enabling 3D printing of free-standing metallic structures without requiring support materials and external pressure.

In a statement, NUS said the team was led by Associate Professor Benjamin Tee from the Department of Materials Science and Engineering in the NUS College of Design and Engineering. They used field’s metal to demonstrate how the new technique can fabricate a wide range of electronics, allowing for more compact designs in devices such as wearable sensors, wireless communication systems and electromagnetic metamaterials.

CHARM3D “exploits the tension between molten metal in a nozzle and the leading edge of the printed part, culminating in uniform, smooth microwire structures with adjustable widths of 100 to 300 microns, roughly the width of one to three strands of human hair.”

This technique also offers faster printing speeds of up to 100 millimetres per second and higher resolutions compared to direct ink writing. 

“CHARM3D forgoes post-treatment steps and enables the fabrication of complex free-standing 3D structures, such as vertical letters, cubic frameworks and scalable helixes. Moreover, these 3D architectures exhibit excellent structural retention with self-healing capabilities, meaning they can automatically recover from mechanical damage and are recyclable,” NUS said. 

So far, the researchers have printed a 3D circuit for wearable battery-free temperature sensors, antennas for wireless vital sign monitoring, and metamaterials for electromagnetic wave manipulation.

The experts believe that CHARM3D can be extended to other types of metals and structural applications. They are also looking for opportunities to commercialise this approach for metal printing.