Alan T. Charlie Johnson is an American physicist, professor in physics and astronomy at the University of Pennsylvania, and was the director of the Nano/Bio Interface Center at the University of Pennsylvania (2014-2017).
Johnson's research spans experimental nanoscale physics, combining nanotechnology and biophysics. His research is involved specifically in transport within nanostructures and carbon nanotubes, which revolves around graphene, DNA, synthetic proteins, and other biomolecules. His research also involves the development of scanning probe techniques to measure electronic properties in nanomaterials and nanodevices.
Johnson is also the Founding Executive Editor of AIP Advances and the co-founder of Graphene Frontiers, LLC.
Education
Johnson received his B.S. in physics from Stanford University in 1984 before going on to earn his Ph.D. in physics from Harvard in 1990, under the supervision of Michael Tinkham. Johnson's thesis was entitled, "Effect of leads and quantum fluctuations on small superconducting tunnel junctions."
During his time at Harvard, Johnson worked as a research assistant, where he started working on nanodevices. He served as a post-doctoral fellow at Delft University of Technology in the Netherlands from 1990 to 1992 before working as a post-doc fellow at National Institute of Standards and Technology in Boulder, Colorado.
Academic work
Professorship at Penn
In 1994, Johnson began working at the University of Pennsylvania in the School of Arts and Sciences. He was promoted from assistant professor to associate professor in 2001. In 2002, Johnson received two secondary appointments in the School of Engineering: an appointment in electrical and systems engineering and an appointment in materials science and engineering. In 2008, he received a full professorship. Johnson served as the associate chair for undergraduate affairs from 2005 to 2011. Since 2011, he has been the associate chair of graduate affairs.
Since he began working at Penn, Johnson has taught both undergraduate and graduate-level courses. These courses range from introductory physics to advanced statistical mechanics and thermodynamics.
Research
Johnson has been a leading researcher at Penn since he began working there in 1994. Prof. Johnson's research focuses on investigating transport phenomena (including charge, energy, and spin) in nanoscale systems such as carbon nanotubes and graphene, along with hybrid nanostructures that incorporate proteins, synthetic peptides, and DNA. Notable recent achievements in Prof. Johnson's research include the development of bio-inspired vapor sensors utilizing carbon nanotube transistors functionalized with mammalian olfactory receptors, the advancement of crystallographic etching techniques for graphene, and the successful large-scale production of graphene oxide membranes.
Prof. Johnson has made significant contributions to the field, including pioneering the concept of Feedback Controlled Electromigration, an atomically precise fabrication technique for nanogap contacts in molecular electronics that is currently pending patent. Additionally, Prof. Johnson has invented a DNA/nanotube gas sensor suitable for electronic nose systems, securing a patent for this innovation. Prof. Johnson's work has also entailed a rigorous quantitative comparison between experimental data and all-atom Molecular Dynamics simulations.