Researchers present work at U nanotech conference

[email protected] The applications of nanotechnology go far beyond the miniature music storage capabilities of the iPod nano . From solar cells to batteries to cancer treatment, a gamut of nanotechnology research is being discussed this week at a three-day conference hosted by the University of Minnesota, which started Tuesday. Thirty-two researchers from various universities and industries are scheduled to present, and hereâÄôs a sample of what University researchers will discuss: Energy Conversion The sunâÄôs rays come in a spectrum of different energies, ranging from high-energy ultraviolet light to visible light to low-energy infrared light. The trouble with current solar cells, chemical engineering and materials science professor David Norris said, is that theyâÄôre really good at converting light into electricity only when it has a particular energy. TheyâÄôre not so efficient at converting light with different energies. His solution is to channel the sunâÄôs energy into a metal, which gets hot and glows, giving off light of a particular color, or energy. The trick here is controlling the color of the metalâÄôs glow by controlling its structure at the nano scale. By doing that, the vast range of light energy available from the sun is converted into a much smaller range that can be used efficiently by the solar cell. The technique isnâÄôt being used in commercially available solar cells, but itâÄôs âÄúsomething weâÄôre exploring as an alternative, because theoretically this approach can have quite high efficiencies,âÄù Norris said. Energy Storage As electronic devices shrink, the batteries needed to power them donâÄôt always keep pace. For example, first generation iPhones werenâÄôt equipped with 3G , or third generation, wireless technology because using it drains the battery so quickly. But better batteries are in sight: chemistry professor Andreas Stein is working to give batteries more bang per square inch by structuring them at the nano level. He has two main goals in the endeavor âÄî to shrink them so they can catch up (or down) with the shrinking dimensions of todayâÄôs tiny electronics, and to increase the speed with which they can charge and discharge. Charging a battery depends on the movement of charged particles through it. By controlling the batteryâÄôs structure on the nano level, scientists can decrease the distance the charged particles have to migrate in order to charge the battery âÄî and that means faster charging. Biomedical Applications Jayanth Panyam , an assistant pharmaceutics professor, is working to make drugs more effective and decrease their side effects by using nanoparticles to direct them to the specific areas in the body where theyâÄôre needed. For example, wrapping chemotherapy drugs in nanoparticles designed to fit into chemical binding sites on tumor tissues could mean decreased side effects for cancer patients. Whether exposure to nanoparticles is incidental âÄî through everyday products that contain them, like sunscreen, clothing and tennis rackets âÄî or intentional, when nanoparticles are used in drugs, itâÄôs important to know how theyâÄôll affect the bodyâÄôs cells. Assistant chemistry professor Christy Haynes has developed a method to do that. To function in a tissue or organ, a cell needs to deliver chemical messages to other cells, and HaynesâÄô group measures how nanoparticles affect a cellâÄôs ability to do that. The ultimate goal, she said, is to figure out rules for nanoparticle design that âÄúlet you control toxicity.âÄù That means being able to design chemotherapy drugs that destroy tumors, while ensuring that sunscreen nanoparticles arenâÄôt harmful to cells. To do that, âÄúyou have to have ways to measure how cells respond,âÄù she said. Though she said her lab is still getting off the ground âÄî Haynes has been at the University for just three years âÄî they already have companies knocking on their door, asking to have their nanoparticles assessed.