Bridging the gap between human and machine

Chao Zhong, a post-doctoral researcher in the Materials Science & Engineering Department, pipets chitin from squid ink onto a microchip. Photo by News

Squid have more use to science than imagined.

A team at the UW has discovered a way to use an organic compound extracted from squid in order to create a transistor that may one day be compatible with biological systems, bridging the gap between human and machine.

Usually, living systems rely on protons and other ions in order to communicate, while electrical devices rely on electrons, meaning they have difficulty working with living systems.

Marco Rolandi, assistant professor in the UW Materials Science & Engineering department, along with his team at the UW, have developed a transistor that is able to convert proton signals into electron signals.

“Attempting to interface electronic components with living systems is not a new branch of research. Pacemakers have been used to monitor and regulate heartbeats in cardiac patients for over five decades,” Rolandi said. “Recently, the ability to miniaturize electronic components has opened the prospect to interface at a smaller and less invasive length scale.”

Since these efforts typically involve moving currents of electrons, there is an issue at the point where living and machine meet because every electron signal from an artificial device needs to be translated into a proton-based signal.

With this in mind, Rolandi and his group made a transistor, or a current switch, that, instead of controlling a current made of electrons, controls a current made of protons, which are positively charged hydrogen ions. These results were recently published in the journal Nature Communications.

“The idea behind it is that perhaps we might be able to start measuring proton currents directly in certain biological processes, in vitro [in a test tube] first, of course,” he said.

Rolandi’s team includes postdoctoral student Chao Zhong, second-year graduate student Yingxin Deng, and master’s student Adnan Kapetanovic.

Zhong, who has been working on the bioprotonic transistor project since June 2009, joined the research team because it he said it “sound[ed] very cool and adds something new to the field.”

He said the lab experimented with many different types of organic material before settling on the squid. After a few failures with different proteins, the team found the squid matter to be the easiest to integrate with the mechanical devices.

The squid’s pen — the piece of the animal the material is extracted from — is an evolutionary leftover, Zhong said. Rolandi and his team have modified the compound’s structure, adding water molecules so it can better integrate with electronic equipment.

This modification allows the protons to “hop” along the water absorbed into the compound and, as a result, proton current can flow.

While the transistor is still in the very beginning stages, in the long term, Rolandi and his team hope to measure and monitor a proton current in certain biological processes.

Reach reporter Asal Shahindoust at news@dailyuw.com.

Please read our Comment policy.