Research Areas


Bioelectromechanical Systems is a cross-disciplinary field that combines engineering and science from the nano to the macro level. In our laboratory, we have developed technology for tissue viability detection, picoliter sample management, and imaging for molecular medicine. Using electrical feedback to perform complex procedures in biotechnology with precision and control, we have established robust methods for single cell analysis, selective cell concentration, and cancer therapy.


Irreversible Electroporation

We have invented a new form of cancer therapy, known as Irreversible Electroporation (IRE). Electroporation is a phenomenon that increases the permeabilization of the cell membrane by exposing the cell to electric pulses. IRE ablates tumors by irreversibly permeabilizing tumor cells through a series of short intense electric pulses from electrodes placed into or around the body. The permanent nanopores in the cells of undesirable tissue eventually leads to cell death without the use of potentially harmful chemotherapeutic drugs. Electroporation can be imaged in real time giving the physician the means to actively monitor the procedure.


Key Highlights

  • IRE is a new minimally invasive, inexpensive surgical technique to treat cancer.
  • IRE treatment is easy to apply and is not affected by local blood flow.
  • IRE does not require the use of adjuvant chemicals or chemotherapeutic drugs.
  • IRE can be monitored and controlled using electrical impedance tomography.

Insulator-Based Dielectrophoresis (iDEP)

Through impedance measurements, the presence and concentration of bioparticles in a suspending medium can be detected in real-time. The platform employs dielectrophoresis technology to selectively separate and concentrate micron and submicron particles based on their unique intrinsic properties. As particles are trapped, the bulk impedance of the collection area changes. Active detection is achieved by tracking instantaneous signal fluctuations at the site where the particles are trapped. This platform is compact, inexpensive and label-free.

Key Highlights

  • Selective concentration of cells, spores and viruses is attainable using dielectrophoresis.
  • Impedance measurements can detect when particles have been collected.
  • These devices are inexpensive and suitable for mass production.

Contactless Dielectrophoresis (cDEP)

Contactless DielectrophoresisDielectrophoresis (DEP) has become a promising technique to separate and identify cells and microparticles suspended in a medium based on their size or electrical properties. Our lab recently developed contactless dielectrophoresis (cDEP) for cell manipulation in which the electrodes are physically isolated from the sample. In cDEP, an electric field is created in the sample microchannel using electrodes inserted into two conductive microchambers, which are separated from the sample channel by thin insulating barriers. These insulating barriers exhibit a capacitive behavior and therefore, an electric field is produced in the main channel by applying an AC field across the barriers. 

 

Key Highlights

  • cDEP identifies cells using their unique electrical properties without fear of contamination from electrodes.
  • The absence of contact between electrodes and sample fluid prevents problems associated with more conventional approaches including contamination, electrochemical effects, bubble formation, and the detrimental effects of joule heating.
  • Inexpensive and simple to fabricate.

Dielectrophoretic Microweaving

We have established a scaffold fabrication method by combining a natural biological process with electrokinetics. The species Acetobacter xylinum are known to excrete microfibrils of cellulose at the liquid/air interface in static cultures. We have proven that electric fields can direct the motion of these bacteria cells without interrupting their natural process to create networks of aligned fibers. By applying dielectrophoresis technology to manipulate bacteria cells, we are capable of creating complex bacterial cellulose (BC) structures for tissue engineering.

Key Highlights

  • BC is biocompatible, abundant in source, and has great mechanical properties.
  • Dielectrophoretic microweaving allows us to vary the mechanical properties of BC.

PI: Rafael V. Davalos, Ph.D.
Professor, Faculty Fellow
CV

329 ICTAS Stanger Street (0298)
Blacksburg, VA 24061
(540) 231-1979

davalos@vt.edu

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About Dr. Davalos