The flubber of the future? It's under development at the University of North Texas (UNT). The so-called "smart gel" has become the catch phrase for water-based, gelatin-like polymers created in labs. The gels have physical properties that change in response to temperature, light, pH and acidic balances, and electric fields. Dr. Zhibing Hu, an associate professor of physics at UNT, heads the research. His work incorporates different materials on a hydrogel surface so that it can change into a specific pattern when induced by a certain stimulus. Gels made to date show lattice or other surface patterns that remain visible or invisible by simply switching between room and body temperature. Possible future uses for this type of gel include acting as an optical gauge that monitors environmental conditions, such as metal ions in water, or as a miniature sensor that can detect enzyme activity. Toys or signs with designs and wording that appear and disappear in response to changing temperatures also would be a possibility. E-mail [email protected].