Nanoscience

Big Solutions at the Nanoscale

By Mark Dwortzan

Sized smaller than a bacterium, extending between one and 100 billionths of a meter, nanostructures are spearheading two gigantic technological trends. First, because of their tiny dimensions, they possess distinct mechanical, chemical, electrical, and optical properties that could be exploited in new, more powerful materials and platforms for computing, communications, imaging, and other applications. Second, since the nanoscale is the same domain at which most biological processes occur, nanostructures may ultimately revolutionize our understanding of human biology and quicken the pace of health care innovation.

For the past four years, experts in science, engineering, medicine, and business at Boston University have collaborated in a growing body of nanoscience and nanotechnology research aimed at furthering both technological trends. Organized by the Center for Nanoscience & Nanobiotechnology (CNN), this research is already bearing fruit. From new design techniques for the ever-shrinking integrated circuit to fast, accurate, needle-free vaccination and drug delivery, CNN is working to bring the benefits of the very small to society at large.

• Nano QuestSince 2004, the Center for Nanoscience & Nanobiotechnology (CNN) has served as the virtual address for all nanoscale research at Boston University. Led by Director Bennett Goldberg, professor of physics and electrical, computer, and biomedical engineering; Associate Director M. Selim Ünlü, professor of electrical engineering; and Associate Director Joyce Wong, associate professor of biomedical engineering, the center brings experts from disparate disciplines together in research projects, seminars, conferences, and other programs to enhance interdisciplinary nanoscale research.
• Needle-Free InoculationToday’s drug and vaccine delivery methods have their drawbacks. Hypodermic needles can hurt and require high volumes to get good results; patches take a long time to diffuse medications into the bloodstream; and ultrasonic methods can be slow and damaging to the skin. None do the job with great speed and precision. But what if a physician or nurse could place a device on your arm just like Star Trek’s Dr. Bones, and psht!—you’re inoculated?
• High-Speed Micro-MappingAn essential research tool in nanoscience and nanotechnology, scanning tunneling microscopy (STM) is a powerful imaging technique that positions a sharp metal wire to within a nanometer above a material’s surface. As the wire probe scans the surface, a tunnel of electrons is sent between the probe tip and the surface. Changes in this current, which is sensitive to the presence or absence of atoms, are then measured. Collectively, these measurements generate an atomic-scale map of the surface, which can be used, for instance, to reveal critical defects in the integrated circuits that control personal computers and other electronic devices.
• Faster, Cheaper Biomolecule AnalysisOver the past decade, Amit Meller, associate professor of biomedical engineering and physics, has used nanopores—akin to wedding rings but only one to five nanometers across—to detect and characterize DNA, RNA, and other biological molecules at the single-molecule level. The pores are sized at about the same scale as the cross-sections of the molecules they are to probe. Among other things, this technology could someday enable physicians to “read” the four bases of a sick patient’s DNA molecule as it is quickly threaded through the nanopore, enabling rapid mapping of large sections of that individual’s genome and a more precise treatment plan.
• Inspecting the Ultra SmallIs there a limit to how much data you can fit in your PalmPilot? The answer may lie at the nanoscale. Over the past decade, as PCs, iPods, and other consumer electronic devices have packed more and more information into faster, higher-density chips, the smallest feature size used in semiconductor circuit fabrication has shrunk by a factor of three. While manufacturers aim to deliver chips free of processing faults and semiconductor defects, today’s nanoscale feature sizes are making semiconductors impossible to inspect with conventional optical imaging methods.