Graphene strips to detect spoiled food, sprayable touchscreens made into fancy shapes and motion capture technology to print directly on expanding organs. Catch up on the monthly news from the field of printed electronics in our July digest below.

A printed graphene strip to detect spoiled food

When meat and fish go bad, they release histamine, an allergen. University of Iowa researchers have created a graphene sensor capable of detecting histamine down to 3.41 parts per million — more than sensitive enough to detect food spoilage. Crucially, graphene is a carbon honeycomb that’s just an atom thick, so the team were able to print their sensors on flexible polymer films using high-resolution aerosol jet printing. This way, they have created a low-cost and accurate biosensor, which can also be used to monitor livestock health, according to the authors.

Sprayable touchscreen breaks free from 2D

A team led by University of Bristol researchers has challenged the idea that touchscreens are limited to 2D and rectangular shapes by developing an interactive display that can be sprayed in any shape. Their approach, called “ProtoSpray”, uses 3D printing to create base electrodes in any desired shape. That base is then sprayed with active materials to produce illumination. “We present a series of ProtoSprayed objects demonstrating how our technique goes beyond existing fabrication techniques by allowing creation of displays on objects with curvatures as complex as a Mobius strip. Our work provides a platform to empower makers to use displays as a fabrication material,” say the authors in their paper.

ProtoSprayed object. © Hanton, Wessely et al. 2020 / Uni. Bristol

Deformable sensors printed on expanding organs

At the University of Minnesota, computer scientists and engineers have developed a 3D printing technique that uses motion capture to cast hydrogel sensors directly on expanding and contracting organs. They tested their procedure by printing a sensor on a ventilating pig lung, demonstrating the compliance of the device to the live, deforming tissue. “The broader idea behind this research is that this is a big step forward to the goal of combining 3D printing technology with surgical robots,” said author Michael McAlpine. These hydrogel sensors could even be applied in diagnosing and monitoring the lungs of patients with COVID-19.

Kick-start your printed electronics project

There is just one month left to take part in INNPAPER’s Open Call — accepting innovative ideas until the 31st August 2020, from across Europe. We are looking for your original proposal of a real-world application for our technology. The winner will get to kick-start the idea with the following: a technical viability assessment, a manufacturing process flow, a roadmap to TRL 7 and an estimation of the cost of the technology. The winner will also gain privileged access to INNPAPER’s pilot printing line, which includes, among other technologies: cutting edge roll to roll pilot coating technology, surface characterisation including AFM and SEM, inks formulation and sheet to sheet printing techniques. We look forward to reading your proposal!