AVS 52nd International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP28
Controlled Passive Transport through a Cellular Mimetic Membrane Consisting of a Stochastic Array of SiO2-coated Vertically Aligned Carbon Nanofibers

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Biomaterial Interfaces Poster Session
Presenter: J.D. Fowlkes, The University of Tennessee, Knoxville
Authors: J.D. Fowlkes, The University of Tennessee, Knoxville
B.L. Fletcher, The University of Tennessee, Knoxville
E.D. Hullander, The University of Tennessee, Knoxville
M.L. Simpson, The University of Tennessee, Knoxville
A.V. Melechko, The University of Tennessee, Knoxville
M.J. Doktycz, Oak Ridge National Laboratory
Correspondent: Click to Email
A cell mimic device has been fabricated for the purpose of mimicking and interfacing to biological processes at the molecular scale. The design of the device addresses the challenge of fabricating and filling small physical volume enclosed membrane structures. The device has the additional advantage of being totally synthetic. The feasibility of using vertically aligned carbon nanofibers (VACNF) as the semi-permeable membrane component of the cell mimic device has been successfully verified by demonstrating the controlled and size-selective transport of nanoscale species by the VACNF membrane. To date, the controlled delivery and containment of picoliter volumes to individual cells has been achieved and the efficacy of the semi-permeable membrane component of the cell mimic to mediate passive diffusion transport has been evaluated. We report here the identification of discrete regimes of membrane transport behavior based on the ability to tailor nanoscale aspects of the membrane pore by controlled oxide deposition. VACNF based membrane elements that are stochastically prepared exhibit a strong statistical nature on the nanoscale. Stochastic features are preferable over patterned ones in terms of reduced fabrication complexity but exhibit statistical deviations that lead to properties that are difficult to predict. We have created a Monte Carlo based simulation to replicate and simulate the stochastic nature of the VACNF membrane and the passive diffusion through the membrane, respectively. The simulation was found to correlate strongly with experimental results. These predictive capabilities help facilitate device design and reduce the number of experimental characterizations. Further, the results reported here implicate stochastic, statistical nanoscale structures as realistic components in integrated devices with stringent requirements on discrete and reproducible behavior.