Research Description

The central theme of the Schmidt group is to combine physical and biological nanofabrication techniques with protein engineering to make new kinds of hybrid devices. To perform this research, we have a highly multidisciplinary laboratory, drawing upon biology, physics, and nanofabrication— capable of performing all aspects of protein production and engineering as well as biophysical measurements of proteins and cells integrated with fabricated structures. My laboratory applies engineering design principles and techniques to create unique biologically functionalized materials. Potential applications are also driven by relationships with industry and medicine.

A major research focus is on the exploration and development of devices functionalized by membrane proteins. These compact and highly versatile proteins can pump ions and analytes, sense touch and temperature, or transduce energy. The functional lifetimes of these proteins can be extended from hours to years through polymer incorporation, allowing their properties to be fully exploited and resulting in new classes of materials. The porosity of some pore proteins can be modulated by pH and electric potential (left). Expanding the palette to other voltage-sensitive membrane proteins leads to the creation of devices which can controllably transport molecules and material specifiable by size and type. This molecular-specific transport can be used as a detection or sortation method. Use of aquaporins, water-specific transport proteins, results in a water filtration and purification apparatus. Combination of different transport proteins in the same device would allow the manipulation and detection of multiple analytes simultaneously, creating a “smart filter” which can pass specific analytes from heterogeneous mixtures, such as blood serum or cytosol; or “lab-on-a-chip”, where biochemical preparations are made which require the dispensation of prescribed amounts of reagents for specified lengths of time. This work can be extended beyond material transport applications: mechanosensitive channel proteins such as MscL have been shown to increase their conductivity upon physical contact; Prestin is an auditory protein which has a natural biological function converting sound waves to electrical signals. Other membrane proteins, such as VR1 and CMR1, have been shown to react to heat and cold, respectively. Engineering these proteins will result in nanoscale mechanical, acoustic, and thermal sensors. The large variety of functions of membrane proteins promises an equally large number of possible applications and devices.

In addition, we are also interested in the development of novel devices and
instrumentation for the study and manipulation of these hybrid systems on the micro
and nanoscales. We combine electrical, optical, and mechanical measurement
and manipulation techniques to create and study hybrid systems. We are guided by
an ultimate goal of creating engineered systems useful in biological, materials, and biomedical applications.