By Erin DostalThe Daily Northwestern
Imagine a car windshield that shows you the time and temperature as you drive, or a visor that projects maps in front of you as you walk to work.
“Invisible” electronics aren’t fiction anymore, and many of them have important, practical applications, according to Tobin J. Marks, a research professor of chemistry at Northwestern.
“You could imagine a display on a window of a building which can … have all sorts of information, and yet still be a transparent window,” Marks said. “Those are the kinds of things we’re thinking about.”
Marks is the leader of a group of NU researchers working on developing transparent electronics, which can be used on everything from car windshields to army helmets. These electronic devices could provide users with maps, the temperature and other pertinent information.
“A transistor enables all the electronics we have around us,” Marks said. “This transistor that we’ve invented has all the capabilities of those transistors except that you can see through it, and you can see through large arrays of them.”
The research group has been working on these specific developments for three or four years, spending the last year putting it all together.
The first demonstrations of this technology were done on glass because it is a relatively easy surface to control. Today, researchers at NU are accomplishing the same thing with plastics, which are more durable, inexpensive and flexible.
The new transparent circuits, made with indium compounds instead of silicon, are not completely revolutionary. They evolved from old technologies.
The group of researchers currently receives funding from various organizations interested in the technology, including the Air Force.
The idea of embedding conductors into transparent materials first was conceived as a way to help pilots defrost their windshields at high altitudes. Today’s applications are more relevant to everyday life.
“In order to fabricate these circuits you need a semi-conductor, a dielectric or insulator, and a conductor,” said Prof. Antonio Facchetti, a researcher in Marks’ group. “What we have discovered here is that we can deposit (onto plastic) all of these materials very near room temperature … these materials are also very transparent.”
Transparent electronics also have many medical applications, Marks said. These include creating visors to give surgeons real-time statistics, such as blood pressure or heart rate, on their patients. They also could help paramedics receive information from a hospital in emergency situations.
“Once you have a circuit you can perform switching, you can perform logic, you can control the pixels on the display … you can have memory, you can have sensing,” Facchetti said. “You can use these circuits to move toward other kinds of functions and devices.”
When they are in full production, Facchetti predicts that these new devices will cost about the same as the current silicon products.
Although he admits that these devices are still in the development stages, Facchetti said he is proud of what the group has accomplished so far.
“It just makes you feel good to belong to a place where we are leading the research,” Facchetti said.
Reach Erin Dostal at [email protected].
