EXQUISITE DESIGN

Mechanical engineering concepts also come into play in designing magnetic data storage, which currently requires heads to fly over a disk with spacing of about 10 nm. Maintaining such flying heights without crashing calls for exquisite design and manufacturing of disks and heads, and fundamental understanding of dynamics, non-continuum fluid mechanics, and surface forces. This has always been part of mechanical engineering and is expected to remain so even as the scales involved shrink.

One of the biggest challenges in magnetic recording is the so-called superparamagnetic limit, which occurs when the volume of a magnetic domain is sufficiently small that thermal fluctuations randomize its polarization. This can be overcome by patterning the magnetic medium. How does one manufacture highly regular magnetic bits with sizes in the range of 20 to 100 nm over a disk surface with diameter of about 3 to 10 cm? The ultimate solution to this problem will be derived from mechanical engineering.
But with all the ways in which mechanical engineering will be crucial to unlocking the potential of nanotechnology, there are challenges as well. University engineering departments must change the way mechanical engineers are educated.

Although some universities claim to have modernized their curricula, a deeper look would suggest that in most cases courses of study reflect the technological needs of the Sputnik era or perhaps an earlier time. Mechanical engineering programs need to ensure that their students are given a solid grounding in the fundamentals of physics, chemistry, and biology.

Approaches must be developed that cultivate a different way of thinking, so that students can develop intuition for phenomena occurring at the nanoscale, as well as gain an understanding for connections that bridge the nanoscale, the mesoscale, and the macroscale.

A gene gun developed at the University of Minnesota sprays a mist of DNA-bearing particles into cells. Similar devices could be used one day to spread manufactured nanoscale objects across relatively broad surfaces.

For this to happen, nanoscience and engineering concepts will need to be integrated into existing undergraduate curricula. Topics such as solid state physics, chemical thermodynamics, surface forces at the atomic and molecular scale, nanofluidics, and motion and behavior of nanoscale structures—most of which receive little if any attention in the traditional undergraduate ME curriculum—will need to be integrated into core courses such as thermodynamics, heat transfer, fluids, statics and dynamics, and manufacturing.

Textbooks need to be written or revised to incorporate this type of material with the core mechanical engineering subjects. Requiring professors of mechanical engineering to take graduate-level refresher courses on these topics is not inconceivable.

Taken together, these changes will represent a new paradigm for the education of mechanical engineers, one that, if done right, will increase disciplinary depth. At the same time, at both the undergraduate and graduate levels, students should be exposed to courses that bring in concepts from multiple disciplines, and faculty and programs must find ways to reduce the barriers to interdisciplinary dialog.

What's more, there should be a strong ethical component to this new teaching paradigm. Like any other technology, nanotechnology can have many unintended consequences that are harmful to our society and to the environment. It can also be used in counterproductive ways that could pose risks to the society.

There are many questions that we engineers must openly discuss: How could nanostructures or manufacturing of nanostructures be harmful to human health? Are there any environmental effects? Could nanotechnology reveal information that infringes on privacy? If improved health diagnostics and therapeutics facilitated by nanotechnology increase lifespan, what effect would the result have on demographics and productivity? Would this technology be accessible to the whole population, or be available to only a certain segment of our society?

It is incumbent upon us engineers to pay close attention to these societal and ethical issues related to nanotechnology. We also need to educate ourselves, the public, and the media about what is realistic and what is not, and in what time frame we could expect nanotechnology to affect our lives. It is our responsibility to do so.

Last year's workshop confirmed the emerging consensus within the mechanical engineering community that nanotechnology will have a profound impact on society and on industry, and that MEs can play a crucial role. Some major recommendations include:

• Sustained support from the National Science Foundation and other funding agencies to maintain long-term, fundamental research in nanoscale science and engineering;

• A focus on research in nanoscale science and engineering that addresses the grand challenges that affect society and humanity;

• Development of education programs that incorporate the essence of nanoscale science and engineering into undergraduate and graduate mechanical engineering curricula;

• Collaboration across disciplines by both NSF and university departments to expose graduate and undergraduate students to interdisciplinary research; and

• Research that seeks integration across scales to exploit nanoscale effects at the micro- and macroscales.