Squishy Electronics Hyung-Jun Koo and Ju-Hee So via IEEE Spectrum

Wet, squishy quasi-liquid electronics could yield better implants that work with the wet, squishy environment of the human body, according to a new study.

A pair of grad students at North Carolina State University presented a paper last week describing a quasi-liquid diode whose electrodes are made of a gallium-indium alloy that is liquid at room temperature. Two hydrogel films are sandwiched between the electrodes — one is doped with an acid and the other holds an alkaline compound.

The interface between the electrodes develops a thin coating of gallium oxide, which creates resistance, as IEEE Spectrum explains. The electrode with the alkaline substance suppresses the formation of this skin. So, applying voltage changes the the thickness of this gallium oxide “skin” — negative voltage makes the oxide thinner, lowering the device’s resistance, and a positive voltage makes it thicker, producing greater resistance.

What’s more, the device retains a memory of its resistance state even after it is turned of, so it acts like a memristor, according to Ju-Hee So, a chemistry grad student who presented a paper on the device last week at the fall meeting of the Materials Research Society in Boston.

The same research lab has previously worked with gallium-indium alloys to build bendy antennae; it can bend and stretch but return to its original shape without breaking. This could make it more useful for future implants like artificial limbs — they would be less rigid and would not need to be isolated from the body's inherent moisture.

So told IEEE Spectrum she believes the alloys in this device would be compatible with human tissue. Eventually, they could be used to build bioelectronic circuits between living tissue and computers, like brain-machine interfaces that would control artificial limbs or artificial neural networks.

[IEEE Spectrum]

1 Comment

Is Hydrogel the golden answer to both lasting brain computer interface and organ transplants? Will the electrodes made from it scare over in a BCI devise or will the blind see? All I can find is that they will not encapsulate with calcium like a stone baby. So, it sounds like it’s the answer to accomplish large caps of silicone with patterns of Hydrogel in them to restore movement and sight. Star wars tech realized?

Furthermore, injected brains of rats heal because blood vessels can grow in Hydrogel preserving the space for rat brains to repair them selves. Now if we take an animal organ like heart bleach out the animals’ cells leaving the collagen scaffolding. Filling the structure with hydrogell then implanting it close to the surface of the skin giving it time to grow a vasculature in the Hydrogel and collagen shell. Then we inject stem cells in the heart until they replace the Hydrogel. Finally we have a complex organ grown with our own stem cells by allowing the body to grow the blood vessels in it first. Next, our new heart is used to replace or assist a damaged heart. All made from our own stem cells so organ rejection problem solved. My point is Hydrogels should be looked at again, and again until they are modified to become the golden solution to both BCI and organ transplants.



June 2013: American Energy Independence

Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.


Online Content Director: Suzanne LaBarre | Email
Senior Editor: Paul Adams | Email
Associate Editor: Dan Nosowitz | Email
Assistant Editor: Colin Lecher | Email
Assistant Editor: Rose Pastore | Email

Contributing Writers:
Rebecca Boyle | Email
Kelsey D. Atherton | Email
Francie Diep | Email
Shaunacy Ferro | Email

circ-top-header.gif
circ-cover.gif
bmxmag-ps