Manos Mavrikakis (left) and Nicholas Abbott have found that liquid crystals used in smart screens can react to chemicals in the atmosphere.
Imagine an app on your phone that can sense whether there is carbon monoxide in a room. If the display doesn’t change, you’re safe. But if the screen changes, “maybe it’s time to get out of the room,” says Manos Mavrikakis.
Mavrikakis is a chemical engineering professor at the UW-Madison who has co-developed a new way of detecting potentially dangerous chemicals using liquid crystals, the same material used in a smartphone touchscreen.
A chemical sensor is “a device that will create some sort of measurable, microscopic, perceivable output in response to the presence of a targeted chemical,” says Nicholas Abbott, the second half of the team. “It could be to provide an alarm to somebody if they’re wearing it.”
The sensors they’re creating are cheaper than what is typical today, largely due to the materials they’re using.
“We’ve done that by creating surfaces that drive the liquid crystal to change orientation when particular chemical species bind to the surface,” says Abbott, an Australian native who has been with the university since 1998. “What makes our system cheap is it’s a material that undergoes a change in optical appearance upon binding of chemicals to a surface, so the cost of the components is very low.”
Mavrikakis, who has been employed at the UW since 1999, has developed a computer program that determines the best components used to detect a specific chemical.
“We quickly screen on the computer which would be the ideal surface — the ideal liquid crystal — for a given chemical you’d like to detect as opposed to running all sorts of experiments pretty much in the dark,” he says. “So in addition to developing technologies that are cheaper than the alternatives, we are making the process of discovering those new technologies cheaper than it used to be.”
Abbott says that with Mavrikakis’ program, they can now “expand the range of things that we can detect using liquid crystals.”
People who work in hospital or factory settings are often exposed to chemicals for which the long-term effects are not known. The team says using their device could provide some research benefits in this regard. It could also, for example, be used to measure the freshness of meat.
“To be able to assess those risks, you have to have measurement tools, and those measurement tools don’t exist at the moment,” Abbott says.
They hope to create small, lightweight, badge-type devices that people can wear in a work setting, or even sensors light enough for unmanned aerial vehicles.
“Coming up with lightweight sensors that don’t intrude on somebody’s work — that’s the sort of thing we want to realize,” Abbott says.
“There are so many chemicals that you want to analyze in everyday life or in professional activities — in chemical plants or hospitals or you name it — and you need to detect small quantities of these chemicals,” says Mavrikakis.
Mavrikakis says this is an example of research done at the university that has practical value and can improve the quality of life. “It’s not pie in the sky, but something very relevant.”