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Electronic Jell-O

Edible 3-D printed electronics made from gelatin and other natural materials

2 min read
Electronic Jell-O
Conductive gelatin can be 3-D printed... and eaten.
Photo: University of Wollongong

The future of medical diagnostics may come in the form of 3-D printed electronic Jell-O, according to an Australian chemist who’s working on developing edible sensors made out of materials like gelatin.

“What I’m suggesting is that we can eat our electronics and then they can perform a function and naturally go away,” says Marc in het Panhuis, associate professor chemistry and head of the soft materials group at the University of Wollongong, Australia.

With his team, in het Panhuis is developing hydrogels made from edible materials, in the hope that they can be used in 3-D printers to make all sorts of devices.

The trouble with hydrogels generally is that they’re fragile, but the group has found that using two different polymers, which form cross-linked molecular chains, makes the gels much more robust. For instance, they mix gelatin with genipin, an anti-inflammatory agent derived from the fruit of the gardenia plant. They also use gellan gum, a thickener used in pastries, sauces, puddings, jellies, and jams. For a crosslinker, they add common salts. Soaking the gellum gum hydrogel in sodium chloride—table salt—for seven days causes it to swell and become more mechanically stable. “Together this gives you a really tough gel,” in het Panhuis told a session at the Materials Research Society’s Fall Meeting in Boston this week.

“What I’m suggesting is that we can eat our electronics and then they can perform a function and naturally go away”

Because hydrogels contain so much water—up to 97.5 percent, in het Panhuis says—they’re naturally conductive, and adding sodium ions makes them more so. Cesium chloride gives even better conductivity that sodium chloride, but of course renders the material inedible.

The materials would be in a liquid state for 3-D printing, but would gel as they cooled over the course of a couple of hours, the same way Jell-O sets in the refrigerator. Using printable materials that have tunable electronic properties, in het Panhuis envisions building biomedical sensors that can be swallowed. One challenge, he says, is figuring out how to read out the information such sensors gather. They’d also need to be made small enough so they can be ingested. He admits the idea is “a little way off.” But with seven years of funding, his goal is to develop something in that time frame.

Longer term, he’s hoping to develop such materials for soft robotics, for instance to make biocompatible actuators that could sense and control the pressure applied by a prosthetic hand. Pliable, conductive materials could also be useful in so-called 4-D printing, in which a device built by a 3-D printer can change its shape over time.

The Conversation (0)

3D-Stacked CMOS Takes Moore’s Law to New Heights

When transistors can’t get any smaller, the only direction is up

10 min read
An image of stacked squares with yellow flat bars through them.
Emily Cooper
Green

Perhaps the most far-reaching technological achievement over the last 50 years has been the steady march toward ever smaller transistors, fitting them more tightly together, and reducing their power consumption. And yet, ever since the two of us started our careers at Intel more than 20 years ago, we’ve been hearing the alarms that the descent into the infinitesimal was about to end. Yet year after year, brilliant new innovations continue to propel the semiconductor industry further.

Along this journey, we engineers had to change the transistor’s architecture as we continued to scale down area and power consumption while boosting performance. The “planar” transistor designs that took us through the last half of the 20th century gave way to 3D fin-shaped devices by the first half of the 2010s. Now, these too have an end date in sight, with a new gate-all-around (GAA) structure rolling into production soon. But we have to look even further ahead because our ability to scale down even this new transistor architecture, which we call RibbonFET, has its limits.

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