Cornell's Duffield Hall Opens for Nanotechnology Research
Cornell's Duffield Hall Opens for Nanotechnology Research
Duffield Hall, a new three-story, $60-million, 155,000-sf interdisciplinary research and instructional center, recently opened its doors to researchers and students on the campus of Cornell University in Ithaca, NY.
The project, which also included remodeling of space in adjacent Phillips Hall, brings together nanotechnology and materials-development groups previously housed in various parts of the Cornell campus. Duffield Hall supports four areas of nanoscale research: nanofabrication (making small devices and structures), nanocharacterization (identifying small things), materials growth (synthesizing materials at the molecular level), and nanobiotechnology (life science research at the DNA level).
Founded in 1868, Cornell is one of the nation's oldest engineering colleges and was the first to award degrees in electrical engineering. Enrollment currently stands at about 12,000 undergrad and 5,000 graduate students. Cornell also has a strong history in nanotechnology. In 1980, the school opened its first sub-micron facility, which later became known as the Cornell Nanofabrication Facility (CNF). Today, Cornell's research budget exceeds $300 million annually.
"Before 'nano' was a well-known term, our researchers were working with technology related to "sub-micron"—or structures that were less than a micron in dimension," says Clifford Pollock, Ph.D., director of the School of Electrical and Computer Engineering at Cornell. "Our sub-micron facility was unique because it was the first federally-funded university facility of its kind."
Pollock served as the faculty leader on the design team and led the programming and siting phases of the Duffield Hall project. He describes the key points of the project's mission statement related to facilities:
• Provide fabrication facilities and capabilities at the sub-micron or the nanometer scale, including structures and devices with dimensions on the order of 100 picometers on materials ranging from semiconductors to polymers.
• Offer materials-growth ability ranging from chemical vapor deposition on large surfaces, to construction of single molecules, including an emphasis on safe handling of exotic and hazardous materials.
• Enable characterization of structure and composition at the atomic level, by providing space that offers the required magnetic field and vibration levels to support electron microscopes and other characterization equipment.
• Enable undergraduate instruction in nanofabrication and characterization for students from across the University.
• Facilitate nanobiotechnology research by providing space that accommodates the diverse requirements of both biological research as well as nanofabrication techniques.
A Look at the Facility
Laboratory Space—In addition to nanotechnology and nanobiotechnology, Duffield Hall includes laboratory space devoted to research in electronics, optoelectronics, material synthesis, processing, and microelectronics. Specific space allocation includes 3,800 sf for characterization labs, 4,300 sf for toxic gas labs for materials growth, and 12,000 sf for wet and dry labs.
Chemical Storage—In adjacent Phillips Hall, 2,000 sf of space serves as storage for Duffield Hall's hazardous materials. Both buildings are connected by a basement corridor, which allows for the safe transport and disposal of chemicals. This dedicated storage space also allows Cornell to adhere to the strict codes and specific practices pertaining to cataloging, characterizing, and storing of hazardous chemicals.
Cleanroom—The first floor of Duffield Hall contains a 20,000-sf, Class 1,000 cleanroom, roughly three times as large as the previous cleanroom available to Cornell researchers. Within the cleanroom, approximately 1,000 sf of space is devoted specifically to biology research.
"Very few cleanrooms have biology space because microelectronics work is often incompatible with sodium chloride, a common compound in biology research," says Pollock. "Because of this, our facility team worked diligently to create sufficient isolation between the two areas, including a floor-to-ceiling dividing wall and separate air handlers."
In addition, researchers using the biology space enter the area with a separate passkey and use different colored gloves to minimize the possibility of cross-contamination with other areas of the cleanroom.
The entire cleanroom is operated and managed by its own staff and serves all building users rather than just one specific professor or research group. Researchers pay a fee to use the cleanroom, which helps Cornell cover the high costs associated with equipment purchases and ongoing operating expenses such as equipment maintenance and repair.
"The downside to this arrangement is that our researchers don't have the luxury of experimenting on individually-designed systems since the cleanroom is devoted to supporting the broader needs of the nanotechnology community," says Pollock. "However, the upside is that our researchers have access to a lot of high-end equipment that most places can't afford. So far, our researchers seem to agree that the collective power of pooling our resources far outweighs having their own personal cleanroom where tools are expensive and hard to maintain."
Toxic Gas Space—Hazardous chemicals that are used to grow new materials, such as silane or arsine, can often emit extremely toxic gases. For this reason, the section within Duffield Hall that contains the Materials Growth Lab was treated as specialized space. This lab space adheres to stricter fire code levels and has more ventilation, including specialty exhaust systems. The lab also has direct access to the chemical storage area so that chemicals can be delivered directly through the secured corridor.
Office Space—Duffield Hall includes two very large (approximately 3,500 sf each), open student areas used as office space and interactive areas for grad students. Each area has large open windows, a large conference room for private meetings, and can be reconfigured quickly and easily using mobile desks and worksurfaces.
The Duffield "Hotel" Concept
Although faculty members might have access to desks within the student area when necessary, Duffield Hall does not include true faculty office space. Instead, Cornell made the strategic decision to leave all faculty offices in their respective departments and buildings around campus.
"We want Duffield Hall to be a place that you move into when you need it, similar to a hotel," says Pollock. "When your research changes direction, you move out and let someone else move in."
He adds that Cornell plans to review this concept every three years to monitor its success. The review will analyze elements such as churn rates, length of time specific researchers occupied Duffield Hall, and costs associated with retrofitting space for new occupants.
Arranging Intellectual Collisions
Pollock also points out that a key design requirement was to create an environment that would foster and promote interaction among all disciplines of the College of Engineering.
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"We purposely designed space where 'intellectual collisions' will occur between researchers," says Pollock. "We did this by including space that encourages casual interaction in or near common facilities such as stairs, alcoves, and conference rooms.
"These intellectual collisions should stimulate new and interesting research ideas since we have a wide range of professionals working within this building, including chemists, engineers, and biologists," he says.
The building also provides visibility for researchers to see colleagues moving from laboratory to offices through the atrium, which connects Duffield Hall with two adjacent structures, Phillips Hall and Upson Hall. The atrium will include collaboration spaces with comfortable furniture, ample power, data connections, and white boards for documenting ideas.
"Visibility into the cleanroom will also encourage similar 'collisions' with the public," says Pollock. "Outside windows will allow visitors to view the research activities taking place within the cleanroom. It is a great way to advertise what we do and to pique the curiosity of future students who want to pursue engineering."
Build on Functionality, not Personality
"We knew that many of the researchers involved in the initial interview process for Duffield Hall might not actually be here when the building was constructed," says Pollock. "For this reason, we treated interview responses as functional descriptions, and not specific labs for individual people. During the design phase the building was mapped out by function rather than by researchers."
While Pollock still recommends this approach, he would tweak the timing slightly.
"This theory works best if you can assign space to specific individuals midway in the construction phase. It would be ideal if final space allocations are made before the first coat of paint goes on any wall," says Pollock.
He adds that this would reduce costly and unnecessary retrofits to accommodate individual preferences within labs and offices. It would also help accommodate proximity requests from specific individuals who wish to be close to other occupants.
Integrate Building Systems Up Front
Facilities as complex as Duffield Hall require an equally complex set of building systems including a fire alarm system, a toxic gas system, and a building control system.
"We wanted all of our various building systems to be able to talk to each other," says Pollock. "However, it was a real challenge to actually make this happen."
To simplify the process he recommends coupling the systems at the design and construction level and assigning one person/company to coordinate the system rather than hiring separate contractors.
"Ideally you need someone who can focus on the whole system, link the various components together, make sure it all works, and most importantly, that it is all compatible," says Pollock. "We tried to buy three different units with specs that claimed there was an interconnect. But it just isn't that simple."
Don't be Afraid to Challenge the Norm
"It's okay to buck advice from consultants if you feel confident following your own best practices," says Pollock. "If you know something has worked well in the past, it will most likely work again."
He points to vibration control within Duffield Hall as one example. Vibration control is critical to the facility since nanocharacterization, photolithography, and e-beam equipment all require very low vibration environments to operate effectively.
"Our design consultants recommended that we construct one big isolation slab to minimize vibration issues for our electron microscopes," says Pollock. "We were reluctant to do this since the CNF, our first nanofab facility, did not use this method."
Instead they opted to stick with the construction method used in CNF. This involved using individual three-feet-thick slabs, isolated from the surrounding slab with a one-inch gap from the slab for each microscope and e-beam tool. The slab-on-grade portion of Duffield Hall's cleanroom is designed to achieve vibrations of less than 50 microinches per second. The second and third-floor labs in Duffield have vibration ratings of 500 to 750 microinches per second. Vibration measurements on these slabs have shown they meet the design goals.
Duffield Hall also presented numerous challenges involving magnetic field minimization. The facilities team did all the basics such as keeping elevators away from characterization suites, and isolating electrical rooms at one end of the building as far from the labs as possible.
"Our team also used extra caution to ensure that no ground currents will flow through any of Duffield Hall's structural steel components," says Pollock. "To do this we did not use any continuous pipes or conductors. Instead we used epoxy-coated rebar in sections of the concrete, so the rebar pieces still touch each other but are insulated by epoxy. Then we tied it all together using plastic insulated steel wire.
"In summary, no matter how challenging your project is, if you put together a good team your project will fly," he says. "Almost any design and construction challenge can be met head-on if your team is willing to integrate facility basics along with all the special requirements of your building's occupants."
By Amy Cammell