Aaron Timperman

Aaron Timperman

Concurrent Professor

Biography

2015-present
Director of Research, Advanced Diagnostics and Therapeutics, University of Notre Dame
2015-present
Concurrent Professor, Department of Chemistry and Biochemistry, University of Notre Dame
2010-2015
Research Chemist, ERDC-CERL, Army Corp of Engineers
2005-2010
Associate Professor of Chemistry, West Virginia University
1999-2005
Assistant Professor of Chemistry, West Virginia University
1997-1999
Postdoctoral Researcher, University of Washington
1995-1997
Postdoctoral Researcher, University of South Florida
1995
Ph.D. in Analytical Chemistry, University of Illinois
1990
B.S. in Chemistry, Saint Louis University

Research Interests

We believe new analytical measurement tools play a critical role in overcoming the grand challenges presented by the complexity of living systems. The wide range of projects in our lab involves microfluidics, chemical separations, proteomics, and a variety of other tools and methods. We approach research in a team oriented manner and work with collaborators at Notre Dame and other institutions. 

A great need exists for the rapid and accurate detection of bacterial and viral pathogens in both clinical and field settings. For medical diagnostics, most gold-standard methods for detection and identification of harmful bacteria take days to produce results. Moreover, adequate sensing for biological warfare agents for both homeland defense and protection of military personnel do not currently exist. Current portable systems rely on selective molecular recognition and are only capable of detecting a relatively limited number of pathogens. In response to these problems, we are working on a novel approach centered on a microfluidic system that augments the selective recognition with physical characterization of the pathogens. Our research is addressing the questions: how many physical parameters can we characterize? With what precision can we characterize these parameters? What improvement in selectivity is gained? Can we differentiate viable and non-viable pathogens? 

There is also a great need for miniature and portable separation systems that can improve the selectivity of sensors. To this aim, we have invented a new microfluidic separation method called traveling wave electrophoresis (TWE). This separation method rivals capillary electrophoresis in performance and has many unique features, including the ability to switch between separative and non-separative transport by simply tuning the frequency. With low voltage (+/- 0.5 V) and power consumption, it will be possible to power and control these devices with cell phones. Currently, the mechanisms of the TWE transport and separation processes are not fully understood. To improve this understanding, we are collaborating with Boyd Edwards from Utah State University, whose team models the separation process. Experimentally, we are focusing on protein and nucleic acid separations, and on creating improved architectures and microfabrication methods. 

Microfluidic devices possess many of the characteristics needed to revolutionize the way that proteomics is performed. Proteins can be extracted from biological samples, separated, prepared for analysis, and injected directly into the mass spectrometer for identification – at minute quantities obtained from single cells and organelles. We are capitalizing on the unique ability of microfluidic systems to fractionate nanoliter volumes of separated protein to create systems that combine the two major approaches to proteomics – bottom-up and top-down proteomics. This unique approach will be applied directly to improve the analysis of post-translational modifications, including phosphorylation.
 
We are continuing our work with nanofluidic/microfluidic interfaces that find applications in water purification, desalination, and sample enrichment. In contrast to other groups, we have focused on electrophoresis dominant concentrators because they are compatible with neutral coatings that reduce unwanted protein adsorption. These devices are being integrated directly into our microfluidic systems for proteome analysis to both enrich and modify the proteins in preparation for analysis. For water purification and desalination, our research is 
aimed at answering the question – what are the limits to increasing the scale of individual units and massively parallel systems?
 
We are also involved in the applications of proteomics to solve important environmental and biomedical problems. We have collaborative projects that use proteomics to discover important interactions in the coral reef ecology and ovarian cancer. Many of these projects are conducted within the context of Notre Dame’s Advanced Diagnostics & Therapeutics initiative, which provides access to a network of research laboratories, graduate fellowship support, and connections to outside collaborators in medical clinics, academia and industry.

Recent Papers

  • Wang,H.; Nandigana, V.R.R.; Jo, K.D.; Aluru, N.R.; Timperman, A.T. "Controlling the ionic current rectification factor of a nanofluidic/microfluidic interface with symmetric nanocapillary interconnects." Anal. Chem. 2015, 87, 3598-3605. 
  • Grimme, J.; King, T.; Jo, K.D.; Cropek, D.; Timperman, A.T. "Development of fieldable lab-on-a-chip systems for detection of a broad array of targets from toxicants to biowarfare agents." J. Nanotech. Eng. Med. 2013, 4, 020904-1 - 020904-8.
  • Jo, K.D.; Schiffbauer, J.E.; Edwards, B.E.; Carroll, R.L.; Timperman, A.T. "Fabrication and performance of a microfluidic traveling-wave electrophoresis system." Analyst 2012, 137, 875-883.
  • Reschke, B.R.; Timperman, A.T. "A study of electrospray ionization emitters with differing geometries with respect to flow rate and electrospray voltage." J. Am. Soc. Mass Spectr. 2011, 22, 2115-2124.
  • Mao, X.; Reschke, B.R.; Timperman, A.T. "Analyte transport past a nanofluidic intermediate electrode junction in a microfluidic device." Electrophoresis 2010, 31, 2686-2694.

 

Contact Information

  • Concurrent Professor
  • Office: 105C McCourtney Hall
  • Phone: 574-631-7868
  • Send an email

Primary Research Areas

Research Specialties