Projects

Projects - Matthew J. Hancock, Ph.D.

B. Math (1998), M. Math (1999), University of Waterloo

Ph.D. Environmental Fluid Dynamics (2005), MIT

Instructor in Applied Mathematics (2005-2008), MIT

Gradients in microchannels. The ability to rapidly generate chemical concentration gradients has important applications in many chemical and biological studies. Dispersion (molecular diffusion + advection by the flow) is used to rapidly establish concentration gradients of molecules (e.g. proteins or toxins) in microchannels. Microchannel design and flow are chosen to optimize gradient formation in conventional microchannel with pumps and portable passive-pump devices. Fundamental results from fluid mechanics support analytical and numerical calculations which validate the experiments and provide optimal microchannel design and flow criteria.

Yanan Du, Jaesool Shim, Mahesh Vidula, Matthew J. Hancock, Edward Lo, Bong Geun Chung, Jeffrey Borenstein, Masoud Khabiry, Donald Cropek and Ali Khademhosseini. Rapid generation of spatially and temporally controllable long-range concentration gradients in a microfluidic device. Lab on a Chip, 2009, DOI: 10.1039/b815990d, in press.

Cell docking and patterning in microchannels. Microstructures that generate shear-protected regions in microchannels can rapidly immobilize cells for cell-based biosensing and drug screening. By altering microstructure geometry, flow circuation in the microstructures force cells the align in specified patterns. Computational flow simulations link the groove geometry and bottom shear stress to the experimental cell docking patterns. Currently, single and double rectangular grooves are being used to align cells along corners. Past work has demonstrated the cell alignment and retention and their dependence on groove geometry. Current work is exploring chemical transport and delivery to the alighned cells, to realize a prototype biosensor.

Masoud Khabiry†, Bong Geun Chung†, Matthew J. Hancock†, Harish Chandra Soundararajan, Yanan Du, Donald Cropek, Won Gu Lee and Ali Khademhosseini. Cell Docking in Double Grooves in a Microfluidic Channel. Small, 2009, DOI: 10.1002/smll.200801644, in press.

High-throughput cell seeding and patterning in microassays. A simple wiping technique is used to localize cells in large arrays of polymeric microwells. This robust method produces cell seeding densities that vary consistently with microwell geometry and cell concentration. A simple theoretical model accurately predicts cell seeding density and seeding efficiency in terms of the design parameters of the microwell array and the cell density. Past work has demonstrated the technique for uniform cell density on 20x20 and 33x33 microarrays. Future work includes generalizing the method to produce gradients in cell seeding density and reduced variation to allow seeding densities down to 1 cell per well.

Lifeng Kang, Mark D. Brigham, Matthew J. Hancock and Ali Khademhosseini. Cell Confinement in Patterned Nanoliter Droplets in a Microwell Array. Submitted Oct 1, 2008.

A hollow sphere soft lithography fabrication approach. The study involves applications of a new hollow sphere (HS) soft lithography method to create spherical chambers. The first application is long-term HD assays which employ the HS as a media reservoir to maintain prolonged and more consistent culture media conditions than conventional hanging drop (HD) assays. ESC aggregates grew for at least 12 days to achieve sizes that were twice as those achieved in conventional HD assays. The geometries of the HDs attached to the rim of HSs were analyzed and shown to agree with existing theory. Future work considers phenomena observed in the fabrication process and also the dynamics of flow and transport within a HS microenvironment.

Won Gu Lee†, Daniel Ortmann†, Matthew J. Hancock and Ali Khademhosseini. A hollow sphere soft lithography approach for long-term hanging drop assays. Submitted to Biotech Bioeng Dec 15, 2008.