Ways to bring about better living through chemistry, the state of the art in brain research and the challenges of creating a single-electron transistor were explored on May 10 during the 2000 Research Directors Conference sponsored by MIT's Industrial Liaison Program.
Speaking on future challenges in their fields as part of a special focus on the sciences were Stephen J. Lippard, the Arthur Amos Noyes Professor of Chemistry and department head; Mriganka Sur, the Sherman Fairchild Professor of Neuroscience and head of brain and cognitive sciences; and Marc A. Kastner, the Donner Professor of Physics, head of physics and director of the Center for Materials Science.
Professor Lippard compared the work of chemists manipulating atoms to create new substances with that of artists creating new works. "Since human imagination has no boundaries, the field of chemistry can never be considered mature," he said.
To predict the direction of its future, however, he polled his colleagues around the country for a "wish list" of what the field may one day accomplish. This is part of what he dubbed "the quiet revolution" in chemistry because these goals are largely unheralded by the media.
The goals include meeting future energy needs, cleaning up the environment or at least producing no more chemical pollutants, creating devices that improve the quality of life as well as furthering basic understanding in the field.
Among chemists' aims are creating self-correcting chemical reactions that produce no hazardous waste or delete their own waste; creating chemical products and processes that do not require the use or generation of hazardous substances and that use renewable resources; creating chemical entities that would allow a patient to get a quick, thorough and noninvasive health profile; coming up with a way to convert methane in the field to methanol for fuel; building bridges out of materials that do not corrode; understanding the structure and function of intermolecular interactions; devising reagents and pathways to break into chemical bonds formerly considered inert; and coming up with catalysts to take up carbon dioxide the way plants do and turn it back into hydrocarbons.
'THE MOST FANTASTIC MACHINE'
Research performed during the past 20 years has shed more light on how our brains work than all of human history combined, Professor Sur said.
The cells that make up what he called "the most fantastic machine in the universe" are different from other cells in that their "language" is electrical. They also make interconnections with each other even though they are not physically touching.
Research on plasticity -- the brain's ability to grow and change -- hints that one day we may be able to grow new brain cells outside the body to replace damaged cells in living brains.
And even though researchers may soon be able to "grow brains in dishes that mimic real brains," Professor Sur emphasized that a brain as we know it can never exist without a body. The body -- it can be a virtual body -- is necessary to provide the visual and auditory input from which the brain learns and grows connections.
"Intelligence involves world knowledge, learning and context," he said. No matter how much time people spend programming computers, computers lack the understanding of words with which to form concepts.
He speculated that consciousness, which is still largely undefined, has something to do with "a complex mixture of loops" that comprise feedback and interconnections between networks of neurons.
Moore's first law is that the number of transistors on a computer chip doubles every 18 months. Professor Kastner cited Moore's second, lesser-known law: the cost of the facilities that build these chips doubles every four years. With the price of these plants now pushing the $1 billion mark, we now need the ability to produce novel devices packed with greater computing power for less money, he said.
One such device may be the single-electron transistor. A typical transistor needs 1,000 electrons to switch from on to off. A single-electron transistor would have the ability to turn on and off each time you add an electron. Right now, these experiments require extremely low temperatures.
Even if the temperatures can be brought up to manageable levels, how do you fabricate these devices? Professor Kastner said that self-assembly, through which scientists create the right conditions for the components' own natural properties to align themselves into a desired configuration, may be the best bet. "Self-assembly is likely to yield a wide variety of new devices if the fabrication gap can be bridged," he said. "But we still need to answer deep scientific questions" before this can be accomplished.
A version of this article appeared in MIT Tech Talk on May 17, 2000.
