Innovation Pipeline

What do an electronic chemical-sniffing device and a glob of chemical-sensitive gel and a Star Trek tractor beam all have in common? They’re recent innovations from the lab benches of MIT. And all provide a glimpse of the future and the new generation of sensing devices that will shape personal lives and business.

The electronic nose from the clever researchers at MIT leverages the technology behind an inkjet printing method. The nose has been modified to detect hazardous materials like carbon monoxide, harmful industrial solvents and, of course, explosives.

What’s especially ingenious about this effort is that the researchers figured a simple way to print thin sensor films onto the ubiquitous microchip. The sniffing work is done by a battery of hollow spheres composed of barium carbonate arranged in a series of nanometer-thick layers. Researchers say human noses contain a similar kind of sensor array that, over time, is trained to respond to various odors.

The second clever piece of sensing innovation is what MIT researchers call a “structured gel”. Its talent is the ability to rapidly change color in response to a variety of stimuli, such as temperature, pressure, salt concentration or humidity. Part of the secret ingredient to this gel is a material that can expand or contract when exposed to stimuli. Changes in the thickness of the gel triggers color shifts, which span the entire visible spectrum.

Researchers accomplished this by starting with a self-assembling block-copolymer thin film. It is comprised of alternating layers of two materials: polystyrene and poly-2-vinyl-pyridine. Researchers say two factors determine the color of light from the gel: the layer’s thickness and its refractive index. By simply altering the thickness of the pyridine layer and stimulating it with pH and salt concentrations, the gel’s color can be changed in a few fractions of a second.

The one sensing device that extends into the sci-fi realm is the so called “tractor beam,” which can be manipulated to pick and move individual cells on the surface of a microchip. Researchers say the innovation could becomee an important tool for both biological and materials research. So far it’s been helping researchers study how neurons communicate by depositing nerve cells on microchips, then monitoring the electrical behavior of those cells.

The idea to use light beams like tweezers has been around for 30 years but the ability to do it in a controlled area for sensing applications is new.

If this is the beginning of the new generation of sensing technology, one can only imagine what will arrive with the combination of microelectronics, nanotech materials and biology in the next 10 years. –Lee Bruno