Biological Actuation, Sensing, and Transport (BAST) at Micro/Nanoscale
Collaborators: Prof. Kenny Breuer (Brown), Prof. Tom Powers (Brown), Prof. Howard Berg (Harvard), Linda Turner (Harvard), Prof. Gail Rosen (Drexel), Prof. George Pappas (UPenn), Prof. Vijay Kumar (UPenn), Prof. Laszlo Kohidai (Semmelweis, Hungary), Prof. Jong Wook Hong (Auburn)
We are studying the practical integration of biomolecular motors for biologically-powered microfluidic systems as well as the development of autonomous bacterial transportation systems for chemotactic biosensing systems. The objective is to demonstrate the use of flagellated bacteria as controllable, reconfigurable elements in a microfluidic network of micro-engineered systems. Bacteria are used both as individual actuators, and in arrays, where the collective effort of the organisms can be applied to carry out useful work in microfluidic environments. The use of flagellated bacteria in an engineered system represents a critical step toward both how global coordination of flagellar filaments can be adapted for use in microscale devices as well as how scientists and engineers can mimic and improve on Nature using modern fabrication and assembly. More Informaiton: Drexel Innovations [Watch Video].
- Fluid Interaction with Nanoscale Structures
- Control of Bacterial Transportation Systems in Microfluidic Networks for a Biofactory
- Novel Bacterial Sensors at Micro/Nanoscale
- Flagella-Templated Nanotube Field-Effect Transistor (FET)
- Chemotaxis Assay for Prokaryotic & Eukaryotic Cells
- Biologically-Inspired Robotic Microswimmers
Single Molecule Biophysics Using Solid-state Nanopore and Nanopore Array
Collaborators: Prof. Guoliang Yang (Drexel), Prof. Jon Spanier (Drexel), Prof. Josh Edel (Imperial, UK), Prof. Per Jemth (Uppsala, Sweden), Prof. Andrew deMello (Imperial, UK), Dr. John Kasianowicz (NIST), Prof. Tim Albrecht (Imperial, UK), Prof. Woong Lee (CNU, Korea)
In the process of adopting a functional structure, proteins must fold from a highly disordered polymer to a discrete and unique 3D shape. The number of potential conformations in the unfolded state is much larger when compared to that of the folded state. Eukaryotic proteins often display remarkably high flexibility. Some proteins are even completely unfolded until they bind their ligand and obtain a well-defined 3D structure. The aim of our research is to define a new nanoanalytical technology which will enable the efficient detection of conformational changes with microsecond resolution in order to answer a fundamental question about intrinsically unstructured proteins, namely, what comes first, folding or unfolding? In addition, we are developing smart solid-state nanopore and nanopore array with superior chemical and mechanical robustness and pore size variability as ultra-fast high throughput nanopore sensors for detecting and sequencing DNA/RNA by parallel optical readout.
Microbial Risk Assessment / Synthesis of Gold Nanorods
Collaborators: Prof. Mira Olson (Drexel), Prof. Sally Solomon (Drexel), Prof. DongKee Yi (Kyungwon, Korea)
In spite of enormous efforts, there has not yet been a report of ultra-fast bacteria/virus detection for the identification of certain types of pathogens. In addition, conventional methods used to disinfect bacteria have proven largely ineffective in treating biofilms, primarily because microoganisms within the bioflim exhibit different properties and survival mechanisms than their planktonic counterpart. We are studying the possibility of using micro/nanosensors and ionic current blockade techniques to detect and configure bacteria/viruses in water as well as the potential of gold nanorods to lyse biofilm communities by quickly transmitting heat through a biofilm.
Vascular Flow Studies : Thrombosis & Arteriosclerosis
Collaborators: Prof. Young Cho (Drexel), Prof. Prashanta Dutta (WSU)
Humans have an intricate hemostatic system to maintain blood in a fluid state under physiologic conditions, but primed to react to vascular injury to limit blood loss by sealing the defect in the vessel. The hemostatic system is a complex set of regulated events for the arrest of posttraumatic hemorrhage, consisting of two major contributors to normal hemostasis: the components of the blood vessel wall and platelets. To understand the hemostatic system and the process of formation of a solid mass inside the blood vessel lumen from the constituents of the blood, we are experimentally investigating the role of platelets as well as the evolution of the atherosclerotic plaque utilizing microfluidics and microscale diagnostic techniques.
Optical Diagnostics for Biological Flows and Microfluidics
In order to investigate biological transport phenomena in micro/nanofluidic environments, we have developed optical diagnostics techniques, such as multi-scale particle image velocimetry (PIV), particle tracking velocimetry (PTV), total internal reflection fluorescence velocimetry (TIRFV), non-labelled bacteria image velocimetry (BIV), molecular tagging fluorescence velocimetry (MTFV), and laser induced fluorescence (LIF). High resolution analysis using local light sources can be accomplished to study micro and nanoscale fluid mechanics and heat and mass transfer.
Nanofabrication and Microfabrication for Biological Applications
Collaborators: Prof. Dongwoo Cho (POSTECH, Korea), Prof. Yury Gogotsi (Drexel)
There exist a wide range of micro/nanofabrication techniques, which directly access to the relevant length scale from nanometer to millimeter. Colloidal lithography has been developed to make a novel array of micro-structures, which can be controlled using the curing temperature-dependent rheological properties of the siloxane elastomer precusor. Microbiological creatures can be patterned on the microstructure demonstrating a potential application for microbioanalytical devices, microfluidics, biological actuation, and bio-MEMS. We have also developed new fabrication approaches of solid-state nanoscale devices, such as nanopore and nanofluidic channel, utilizing focused ion beam (FIB) and scanning transmission electron microscope (STEM). With nanofabricated devices, we are exploring structures, dynamics, interactions of single DNA/RNA molecules and virus translocating through nanometer sized geometries.
For questions about research, click here. last updated Jan. 5th. 2008
Past Projects
- Fabrication of Single-digit Nanometer Solid-state Pore for Single Molecule Analysis
- Bacterial Flows: Mixing and Pumping in Microfluidic Systems Using Flagellated Bacteria
- Microfluidic Flow Control Using Electroosmosis