THERE'S NOTHING STRANGE about Jell-O congealing when the mercury drops. It is trickier to make a gel that hardens in heat and turns back into a liquid when cooled. Massachusetts Institute of Technology physicist Toyoichi Tanaka has spent most of his 20-year career researching such unusual polymer gels. His patented "smart hydrogels" jump through phase changes, shrink down, or expand thousands of times in response to changes in temperature, light, electric or magnetic fields, or chemical stimuli.
These aren't idle parlor tricks. The company Tanaka co-founded in 1992 in Bedford, Mass., called Gel Sciences Inc., will soon start spinning gels into commercial products. First out the door, in mid-1996, will be a golf shoe designed with partner Titleist & Foot-Joy Worldwide in Fairhaven, Mass. A gel in the shoe upper warms to the wearer's body temperature and matches the contours of the wearer's foot: If that aching foot starts to swell, the shoe adjusts.
Next, the company's medical subsidiary, called GelMed, will seek Food & Drug Administration approval to test therapeutic and cosmetic gels. One of these, a "reverse" thermal gel that is liquid at room temperature and viscous at 98.6 degrees, could be used to deliver eye medications. A few drops would spread evenly over the eye to form an ultrathin liquid sheath, allowing for continuous, slow release of a drug. GelMed is in early discussions with several drug companies.