As electronics become smaller, lighter, and more flexible—think smartphones, fitness trackers, and wireless earbuds—researchers are also looking for ways to make these devices more sustainable.
A team from the Singapore University of Technology and Design (SUTD), led by Associate Professor Michinao Hashimoto, has come up with a breakthrough: a new 3D printing method that uses biodegradable materials to create electrically conductive components.
Traditionally, making electronic parts involves plastics and metals that are harmful to the environment and hard to recycle.
But the SUTD team developed a way to print with cellulose acetate, a plastic made from plants that breaks down more easily in nature. The challenge? This material can’t handle high heat, which most 3D printers rely on.
Other methods, like pouring liquid films, don’t offer enough precision to build complex electronic parts.
To solve this, the team used direct ink writing, a type of 3D printing done at room temperature.
They made a custom ink by dissolving cellulose acetate in acetone (a common, low-toxicity solvent) and mixing it with graphite particles—the same substance found in pencils—to give the material the ability to conduct electricity.
But at first, this ink was hard to control; it spread too easily when printed in air.
The real innovation came when the researchers began printing the ink into water instead of air.
The water quickly pulled out the acetone, a process known as immersion precipitation, causing the material to solidify immediately and hold its shape.
This method allowed for clean, well-defined printing and avoided problems like ink spreading or nozzle clogging.
What makes this even more impressive is the high amount of graphite they were able to use—up to 60% by weight, much more than most printing methods can handle.
This high filler content resulted in printed materials that were strongly conductive—able to power devices like LED lights—and flexible enough for uses such as bendable circuits and sensors.
The team also showed how this technique could print complex shapes, like spiral structures, by using a soft gel as a support material. This meant they could create overhanging parts without the need for extra supports, which would normally be printed and removed later.
Because they use biodegradable materials like cellulose and graphite, and a safe, fast-evaporating solvent, the method is both practical and environmentally friendly.
The researchers plan to expand their work to include other types of eco-materials and test how their creations perform in everyday use.
Their goal is to develop a low-cost, scalable way to make flexible, sustainable electronics for a cleaner future.
Source: KSR.
