If you’re an electrical engineer, 3D printing has long been a valuable tool for carrying out tasks like printing prototype housings or cases for your projects. But the 3D printing of electronic components themselves is also a growing field. This is something researchers from the U.K.’s University of Nottingham are helping with — courtesy of a newly invented “breakthrough” approach to printing fully functional electronic circuits that could help transform the way we create components.

“Here at the Center for Additive Manufacturing, we’re exploring ways of developing additive manufacturing beyond single material deposition to the ability to manufacture a working system straight out of the machine,” Professor Chris Tuck, professor of materials engineering and lead investigator of the study, told Digital Trends.

The researchers’ new approach involves printing circuits made of electrically conductive metallic inks and insulating polymeric inks. These can be produced in a single inkjet printing process, using an ultraviolet light to solidify the inks. This solidification process takes less than one minute per layer, which is far quicker than other approaches that made it impractical to consider printing objects with hundreds of different layers.

The approach also allows for the printing of multiple materials in one object. The researchers hope that this will make it possible to print more ambitious electronic items in the future — for example, a wristband with both pressure sensor and wireless communication circuitry.

“This means we can begin to explore producing three-dimensional circuits and structures in a single manufacturing step,” Tuck continued. As with 3D printing as a whole, what makes this work exciting is that engineers would be able to more easily customize each item to a certain use case.

Tuck’s colleague, engineering research fellow Ehab Saleh, told us that the team has already been approached to use the technique to work on some “exciting applications,” although the researchers are not able to reveal specifics as of yet. “The outcome of the work could enable many real-world applications in electronics where a complete device with a complex geometry could be 3D printed with a press of a button,” Saleh said.

Scientists in China have developed a method to print flexible electronic circuits on paper using liquid metal ink.

AsianScientist (May 9, 2013) – Scientists in China have developed a method to print flexible electronic circuits on paper using liquid metal ink, which paves the way for a simple, low-cost method for printing paper electronics.

To produce conventional printed circuit boards or electronic devices, metal is generally deposited on a surface by complex methods, which consume much time and energy. Paper is an attractive material for making flexible electronics because it is cheap and easy to work with. However, unlike normal print ink, electrical inks are difficult to print onto paper because of their extremely large surface tension.

A team of scientists led by Prof. Jing Liu from the Chinese Academy of Sciences in Beijing, China, has overcome some of the issues that have impeded reliable printing of circuits. Publishing in the journal Scientific Reports, they describe the concept of Printed-Circuits-on-Paper (PCP), essentially a printing principle for 3D functional electronics devices.

Firstly, the scientists improved the adhesion of liquid metal alloy ink by an oxidation strategy. To overcome the high surface tension of the ink, the team designed new printing machinery with a brush-like porous pinhead. Lastly, they identified specially coated paper that offered the best surface to which the ink could attach. Importantly, the whole printing process can be performed at room temperature, “just like printing pictures on paper on an office printer,” says Prof. Liu.

Using their new technique, the researchers have successfully printed typical circuits and functional components such as conductive wires, inductance coils and flexible antennae. By incorporating vulcanized silicone rubber as isolating inks, the team has also developed a way to directly print a three-dimensional (3D) hybrid electro-mechanical device, an advance over currently available 3D printers that can only print mechanical objects without electronics inside.

Prof. Liu hopes his team’s new technique could be used in applications as varied as rapid-prototyping circuits, integrated circuits on paper, sensors, 3D mechanical switches and antennae, electric solar cell arrays and functional radio-frequency identification (RFID) tags on books.

Looking to the future, Prof. Liu says, “So far, the prototyping machine is still somewhat expensive. We are striving to make it affordable for daily routine use, say, offering an ordinary office electronics printer. In addition, better circuital uniformity and resolution can still be possible.”