AVS 52nd International Symposium
    MEMS and NEMS Monday Sessions
       Session MN-MoA

Invited Paper MN-MoA3
Biofabrication: Enlisting Biological Materials for Fabrication

Monday, October 31, 2005, 2:40 pm, Room 207

Session: Materials and Processes for Bio-MEMS and Bio-NEMS
Presenter: G.F. Payne, University of Maryland Biotechnology Institute
Authors: G.F. Payne, University of Maryland Biotechnology Institute
L.Q. Wu, University of Maryland Biotechnology Institute
H. Yi, University of Maryland Biotechnology Institute
W.E. Bentley, University of Maryland Biotechnology Institute
J.N. Culver, University of Maryland Biotechnology Institute
G.W. Rubloff, University of Maryland
R. Ghodssi, University of Maryland
Correspondent: Click to Email
Biological materials offer unique properties that facilitate fabrication. Well-known are the self-assembly properties of biological materials that enable the bottom-up self-fabrication of nano-scale structures (e.g. nanowires and nanotubes). Yet, biological materials offer additional properties. They can be acted upon by enzymes enabling highly selective biocatalysts to be enlisted for enzymatic-assembly. And, biological materials often possess stimuli-responsive properties that enable a range of external stimuli to be enlisted for directed-assembly. We are studying the stimuli-responsive amino-polysaccharide chitosan as a versatile interface material. Chitosan's pH-responsive electrostatic properties allow its directed assembly (i.e. electrodeposition) in response to localized electrical signals that can be imposed from electrodes. Chitosan's directed-assembly can be controlled by controlling deposition conditions, and high lateral resolutions have been observed when the electrical signals are imposed from micropatterned electrodes. Once neutralized, the chitosan deposit is stable (chitosan is insoluble under neutral and basic conditions) although it can be re-solubilized by washing with mild acid. In addition to its stimuli-responsive properties, chitosan also offers chemical properties that permit the facile conjugation of proteins and nucleic acids to previously-deposited chitosan. These chitosan-bound proteins and nucleic acids can confer important functional properties (e.g. recognition, catalysis and binding). We are particularly interested in using the hybridization capabilities of chitosan-bound nucleic acids to serve as "nucleation sites" for the self-assembly of higher-ordered structures. Together, the results demonstrate that chitosanâ?Ts unique properties enable the integration of biological materials for biofabrication at the micro- and nano-scale.