The Tiny World of Nanoscience is a Big Thing on Campus
The Tiny World of Nanoscience Is a Big Thing on Campus
By Christine Palm
If ever a branch of science embodied “small but mighty,” it would have to be nanoscience. In this world, the properties of objects change so dramatically that the tinier something is, the more powerful it often becomes. And the myriad possibilities stemming from those changes makes nanoscience riveting to faculty and students at Mount Holyoke. With passion and acumen, researchers here are probing this new, invisible frontier that is already an integral part of all our lives—whether or not we know it. Within nanoscience’s tiny, mysterious world lies the key to solving everyday problems from medicine to manufacturing.
To the uninitiated, nanoscience seems ineffable; experiments and procedures are conducted at so infinitesimal a scale that it’s hard to conceive of their size, much less their importance. However, chemical, physical, and biological changes taking place at the nanoscale affect virtually every aspect of our lives, allowing us to experience everything from the smell of freshly baked cookies to the sound of the 1,000th song on our iPods.
Size Matters
The prefix “nano” comes from the Greek word for dwarf, and nano objects are seriously small. To put this in some sort of perspective, a simple germ is about 1,000 nanometers. The tiny switches inside computers are only 100 nanometers wide; about 1,000 such switches would fit across the width of a human hair.
Associate Professor of Chemistry Wei Chen (right) starts with something tangible to help explain why the nanoscale intrigues scientists. “Imagine breaking a concrete block into chunks,” she says rapidly and energetically. “Instantly, the amount of surface area increases, and the smaller something is, the greater the surface area-to-volume ratio.” But does this matter?
“It changes everything!” Chen exclaims. “For instance, on the nanoscale, gold is a brilliant crimson—so red it was used in [medieval] stained-glass window-making. Today, nanoscopic gold is used to brighten the area where a tumor is growing—to ‘tag’ it, if you will, so that a sensing device can mark exactly where the cancer is.” Before too long, Chen says, this will allow doctors to treat only the cancerous area of the body and leave healthy cells alone.
“Nanoscopic things are wonderful catalysts; the greater the surface-area-to-volume ratio, the greater its potential to affect other objects and materials,” says Chen. “As a chemist, I just love the way the surface properties change so completely at that scale.” Carbon is one example of just how completely: although normally soft (as in a pencil lead), carbon, when formed as nanotubes, becomes stronger than steel and one-sixth its weight.
“The terms ‘nanotechnology’ and ‘nanoscale’ usually make people think of tiny little computerized items that will be used only in machines or technical applications, when really nanoscience is relevant to everyday life,” says Angela M. DiCiccio ’08, who is working with Chen on nanoparticle research.
“When someone wears a patch that allows drugs to diffuse into the body, or someone uses biosensors to image an implant or repaired tissues, nanoscale technology is in place. Research on the nanolevel is all about understanding the smallest basics of our beings and finding out how to fix tiny problems that lead to much larger issues.”
Through grants from the National Science Foundation and Nanotechnology Undergraduate Education, Chen is collaborating with MHC students on a project to incorporate metal nanoparticles into biocompatible hydrogels made of polyvinyl alcohol (similar to contact-lens surfaces of such everyday objects as aluminum foil. Magnified millions of times, the shiny and dull sides of the foil take on remarkably different properties, one appearing oily and the other as deeply cratered as the moon.
“My passion is understanding the physical principles that make something possible,” says Gomez. Her students are studying crystal and ceramic nanostructures to ascertain their proton-conducting ability, which allows them to generate electricity in a fuel cell. In a ceramics course, Gomez challenges students to consider piezoelectric devices that can convert mechanical energy into batteries nor an external power source.
Small Is Cool
Over in Kendade Hall, too, the invisible world of nanoscience is having a visible effect. Dozens of courses across scientific disciplines introduce nanoscience to Mount Holyoke’s students, and professors and students are collaborating on nanoscience research in dramatic, diverse ways.
“To understand nanoscience, we must move from classical mechanics—Newton and his apple—to quantum mechanics, where the very nature of how particles behave shifts,” says Associate Professor of Physics Janice Hudgings. “For instance, at the nanoscale, electrons no longer have definite positions, they have only a probability of being in a given location. And while this sounds esoteric, one of the things I enjoy most about quantum mechanics is that while it’s closely intermingled with philosophy, there are experimental proofs and demonstrations you can perform. The theories are accessible on an undergraduate level, and because of the remarkable facilities here, the undergrads can be introduced to work done elsewhere only at a graduate level.”
“Small is cool, as Kathy Aidala, our research adviser, often points out,” says Tolu Ogunbekun ’09 (left). “It opens a new branch electrical energy. This has enormous potential. For example, if someone could, by simply bending his arm, cause muscle contractions that convert mechanical energy to electrical voltage, doctors could implant in that patient a wireless device for biomedical monitoring that would require neither to see how they react, with an ultimate eye toward biomedical diagnostic applications.
Next door to Chen’s office in Carr Hall, Assistant Professor of Chemistry Maria Gomez asks her General Chemistry students to study, at the nanoscopic level, the of exciting research, and I’m very happy Mount Holyoke hasn’t used age or level of education as a bar to the exciting research opportunities in the world. We might not be as learned as graduate students, but we sure do learn new things every day. In fact, sometimes not knowing exactly what to do gives us a chance to … experiment and find new and sometimes more efficient ways of doing something.”
“We’re studying diblock polymers,” says Danti Chen ’09, who works with Clare Boothe Luce Assistant Professor of Physics Kathy Aidala and Ward Lopes, visiting assistant professor in physics. “More specifically, we are looking at how defects move around when the polymer is heated to 210 degrees Celsius. This is very exciting because everything is in nanoscale and not many people have studied it. Studying defects allows us to see how the molecules organize themselves, or self-assemble. We can use their ability to self-assemble to produce nanowires.” And these, Danti Chen explains, have a practical application.
“Nanodevices can work just like the semi conductors in computers, but they can hold much more information per unit area, which will boost the storage capacity. We’ll be able to write more information in a smaller area, and hopefully in a cheaper manner. This sure sounds wonderful, doesn’t it?” The end result might be cheaper, smaller storage mechanisms that hold far more information than is possible today. “This would be especially useful for military personnel, who need to be able to transport lots of information on small, highly portable computers,” says Chen’s professor, Kathy Aidala.
The Right Tools
Regardless of the specifics of the professors’ research, all are aided by several remarkable tools. Most notable is an astonishingly accurate microscope— used for atomic force microscopy and scanning probe microscopy—that is usually found in only the most cutting-edge of high-tech companies.
Professor Megan Núñez, for example, uses atomic force microscopy to study how a small predatory bacterium, Bdellovibrio bacteriovorus, behaves as it hunts and eats its prey. “We poke at it, literally, and measure its physical properties,” explains Núñez, Clare Booth Luce Assistant Professor of Chemistry. “We also extract molecules from the Bdellovibrios and their prey, such as E. coli, and use them to make artificial membranes.” In a world in which humans are suffering from bacterial infections increasingly resistant to antibiotics, a small, predatory bacterium could be an important medical breakthrough.
None of this research would be possible without state-of-the-art laboratories. “Our facilities are phenomenal,” Janice Hudgings says. “We’re extremely fortunate as a small college to have a state-of-the-art scanning probe microscope and a critical mass of really engaged colleagues who keep the energy high. No one’s off in a corner doing her own thing. This is a research-intense faculty, we are backed up by tons of support, and we enjoy a student body that is smart, engaged, helpful, and enthusiastic. They’re always willing to show their joy at the wonder of things.”
In fact, the energy shown for science on the nanoscale is palpable in classrooms, labs, and even hallways. “The advantage of being at a place like Mount Holyoke is that all of the available tools are available to us,” says Angela DiCiccio. “As undergraduates we can prepare our own samples and run them on the TEM [transmission electron microscopy] to see things at the atomic and molecular level, or we can sign up for NMR [nuclear magnetic resonance spectroscopy] time and analyze a spectra that describes the bonding of molecules. At a graduate institution I can only imagine that the availability of resources might be more limited, even if there happen to be more of them around.”
In Janice Hudgings’s research on how light and electricity interact, the college’s microscopy facilities are invaluable. “If I shine a light on a device or on some material, can I get electricity out of it?” she wonders. “And conversely, if I have something that generates electricity, can I get light from it?”
Her research with such optoelectronic devices as lasers and optical amplifiers has everyday applications. Without such nanotechnology, there would be no solar cells for use in alternative energy, no information stored on CDs, no integrated circuitry inside a computer, and none of the latest developments in telecommunications, since words spoken into a cell phone are actually carried to their destination by waves of light, not sound.
Sometimes, experiments in nanotechnology can take a researcher unexpected places. For example, as part of their research in thermal imaging of photonic integrated circuits, Hudgings and Rajeev Ram, a research collaborator from MIT with whom she was granted NSF funding, developed an apparatus and technique for thermoreflectance imaging, which the collaborators hope to market to other researchers. Mount Holyoke owns the patent, and they are exploring routes to commercialization of their work, with help from some MHC trustees.
Linking Past and Future
Whether in chemistry, biology, or physics, nanoscience is revolutionizing our world. And here on campus, more of that subatomic world is being revealed each day.
On their way to class on the second floor of Kendade Hall, Mount Holyoke science students pass by a poster of Hypatia of Alexandria (c. 370–415), the brilliant scientist murdered by a mob for her bold lectures in mechanics, astronomy, mathematics, and philosophy. More than a millennium and a half after that crowd hauled her from her classroom and killed her, Hypatia’s intellectual heirs—young women like Danti Chen, Angela DiCiccio, Tolu Ogunbekun, and dozens of others—continue her legacy through strides in nanoscience. It is surely one of the most intriguing disciplines built on the foundation she laid. Hypatia, whose death is said to have halted scientific progress for a thousand years, seems to look on in satisfied vindication.
“Reserve your right to think …”—Hypatia of Alexandria
Nanopossibilities
Nanoscientists are still working to turn these ideas into reality.
• Nanorobots that will scour the cholesterol from inside our arteries like tiny scrub brushes
• Nanoscale machine gears that are more precise and won’t wear out due to abrasion
• Fabrics that feel like cotton but are much stronger
• Neurons reengineered to communicate directly with artificial limbs
• “Living machines” that, for example, use proteins from spinach to create electronic circuits for use in solar cells
• Materials manufactured without waste by building exactly what is needed one atom at a time
Nanoproducts: Right Here, Right Now
Among the hundreds of existing consumer products using nanotechnology are items like the canola oil shown here, found in many homes, possibly including yours.
• Sunscreen
• Air freshener
• Computer processors
• Antibacterial kitchenware
• Toothpaste
• Tennis rackets
• Hiking pants
See the whole list at http://www.nanotechproject.org/index.php?id=44
Photos (other than Hudgings') by Paul Schnaittacher
