ARLINGTON, Va. -- On March 6, the Air Force Office of Scientific Research in Arlington, Va., hosted a presentation by Dr. Chad Mirkin from Northwestern University.
Professor Mirkin is a chemist and a world-renowned nanoscience expert who is known for his development of nanoparticle-based biodetection schemes, the invention of spherical nucleic acids (SNAs) and Dip-Pen Nanolithography (DPN), and his contributions to supramolecular chemistry, nanoelectronics, and nanooptics. He is the author of over 480 manuscripts, holds over 440 patents and applications, and is the founder of three companies, which specialize in commercializing nanotechnology applications.
Dr. Mirkin's presentation was part of a continuing series of events planned throughout the coming year as part of AFOSR's 60th anniversary celebration and was scheduled during AFOSR's annual Spring Review program, taking advantage of an audience from numerous science and technology organizations holding wide-ranging scientific and engineering interests.
Dr. Mirkin informed and entertained a large gathering of attendees with a presentation regarding the history and current efforts in the ever-widening and important field of nanotechnology. The talk was also broadcast live over the web, enhancing AFOSR outreach efforts, with questions from the virtual audience being fielded in real time via email and Twitter.
Dr. Mirkin began his talk by noting that his field is complicated by having strong roots in both real science and science fiction and that his early years were devoted to a couple of very aggressive, field challenging, and field changing ideas. But Dr. Mirkin also noted that without the support of the Air Force Office of Scientific Research, his outside of the box ideas would have never been realized. With AFOSR funding, his early concepts have evolved into components of what is today the basis for [worldwide industries. At Northwestern University alone, the International Institute for Nanotechnology features a $600 million research and infrastructure program with over 240 contributing faculty and with over 500 post-doctoral and graduate student researchers.
A basic research investigator funded by AFOSR since 1997, Dr. Mirkin pioneered the field of Dip-Pen Nanolithography (DPN) with his seminal research highlighted in the journal Science in January 1999. DPN is a technology that builds nanoscale structures and patterns by drawing molecules directly onto a substrate. This process was achieved by employing an Atomic Force Microscope (AFM), the tip of which has the innate capability to precisely place items and draw lines at the nanoscale level. The Atomic Force Microscope was basically an extremely small paint brush. Mirkin's fundamental contribution was recognizing that it could be used to print structures on a surface through materials- rather than energy- delivery though with the latter being the approach taken by all previous researchers.
Since 1999, the Mirkin DPN process has changed dramatically. His current inventions have eliminated the need for cantilevers and rely on arrays of soft pyramids made in the form of an elastomeric stamp adhered to a transparent flat backing layer. This Polymer Pen Lithography (PPL) technique permits a Massively Parallel Dip-Pen Nanolithography capability resulting in high resolution, high throughput and mask-free nanofabrication. By putting thermal and electrostatic actuators on the pens, it allows for the specific control of individual or group pen placement, so that highly customized structures can be made. In subsequent years, those highly customized structures and related enhanced procedures have blossomed into a wide variety of research interests, to include: biomedical and human performance applications, environmental sensors/remediation materials, production of electronics/photonics materials, security devices, energy harvesting and storage applications, and, of course, sophisticated nanolithography and nanofabrication tools.
In addition to his work with DPN, Dr. Mirkin highlighted a current program emphasis regarding programmable atoms, which employs spherical nucleic acids (SNAs, spherical particles coated with a dense layer of highly oriented DNA) to literally fabricate new crystal structures on command. These particles also form the basis for diagnostic tests that allow one to screen chemical and biological markers and literally measure intercellular genetic content in live cells, in real time.
Lastly, Dr. Mirkin explained the invention and development of a process for doing lithography on a nanowire, otherwise known as On-Wire Lithography or OWL. The utility of a nanowire derives from its dimensions and composition. OWL allows one to selectively create gaps and disk architectures along the long wire axis. The result is the ability to create nanostructures that have properties not associated with materials made via conventional synthesis and devices that can be used to make fundamental measurements on individual molecules. OWL has been used for the design and fabrication of novel disk arrays that have optimized Raman hot spots and can be used for the labeling and taggant processes for biological systems and even the construction of catalytic nano-rotors.
Dr. Mirkin¹s cutting edge review enlightened the audience about a future that is inexorably affected by the many advances in nanolithography and the many advantages they offer. New nanolithography based platforms available for basic research; citing the ability to accomplish materials by design; the promise of single entity/non-toxic gene regulation agents; routes to compact power generation, conversion and storage systems. In addition, a new generation of integrated electronics and photonics; ultra-sensitive and specific sensor systems; and new materials for overt and covert tagging and authentication have their genesis in this technology.
It was on 29 December 1959 that renowned physicist and Nobel laureate Richard P. Feynman delivered his famous talk entitled, "There¹s Plenty of Room at the Bottom." In this lecture he addressed the problem of manipulating and controlling things on a small scale, and the enormous amounts of information that can be carried or placed in an exceedingly small space. Although it took about forty years for the appropriate practical technology to arrive at that capability, AFOSR assisted a talented research chemist in helping to not only realize Feynman's vision, but to move far beyond it. Dr. Mirkin concluded his remarks by stating: "I would not be here today if it were not for the Air Force Office of Scientific Research. It's been a fantastic journey."
AFOSR continues to expand the horizon of scientific knowledge through its leadership and management of the Air Force's basic research program. As a vital component of the Air Force Research Laboratory, AFOSR's mission is to discover, shape, and champion basic science that profoundly impacts the future Air Force.