Time equals money. But so does weight—when it comes to the films used in computers and optical telecommunications. Shaving off pounds from these devices could mean huge benefits for microelectronics as well as for satellites or spacecraft, where launching costs around $50,000 per kilogram (2.2 pounds).
A new recruit to the Institute, Dr. Milko van der Boom of the Department of Organic Chemistry, is working to create thin films with such desirable qualities as low weight and long-term thermostability. He is targeting an “all-organic” product, which he hopes will replace today’s inorganic materials. The rationale is simple. Organic films would be much easier to modify, offering far better, cheaper devices that could even be introduced into home appliances, revolutionizing the electronics industry.
The challenges of creating these films, however, are considerable—from effectively integrating organic molecules into thin films, to creating films that are thick enough to efficiently convey the light signal.
To address these challenges, Dr. Van der Boom and groups led by Prof. Tobin J. Marks and Prof. Pulak Dutta at Northwestern University have created a novel bottom-up growth method. The teams begin by producing custom-designed organic molecules, which they then integrate into the film, building it up layer by layer (each layer is only 2.5 nanometers thick).
They had to “trick” nature to do so, organizing the molecules in a novel arrangement in which the molecules are all aligned in one direction. “Nature prefers a random orientation,” says Dr. Van der Boom.
Another innovation is the introduction of polymers that help to organize the films, creating smoother materials. Using this approach, the teams have created highly organized films consisting of 100 layers—a marked improvement over the average 10-layer films achieved to date. The team has recently created the first prototype electro-optic modulators based on these films.