We report a novel approach for producing carbon nanotube fibers (CNF) composed with the polysaccharide agarose. Current attempts to make CNF’s require the use of a polymer or precipitating agent in the coagulating bath that may have negative effects in biomedical applications. We show that by taking advantage of the gelation properties of agarose one can substitute the bath with distilled water or ethanol and hence reduce the complexity associated with alternating the bath components or the use of organic solvents. We also demonstrate that these CNF can be chemically functionalized to express biological moieties through available free hydroxyl groups in agarose. We corroborate that agarose CNF are not only conductive and nontoxic, but their functionalization can facilitate cell attachment and response both in vitro and in vivo. Our findings suggest that agarose/CNT hybrid materials are excellent candidates for applications involving neural tissue engineering and biointerfacing with the nervous system.

We demonstrate the biocompatibility of carbon nanotube fibers (CNFs) fabricated from single-wall carbon nanotubes. Produced by a particle-coagulation spinning process, CNFs are "hair-like" conductive microwires, which uniquely combine properties of porous nanostructured scaffolds, high-area electrodes, and permeable microfluidic conduits. We report that CNFs are nontoxic and support the attachment, spreading, and growth of mammalian cells and the extension of processes from neurons in vitro. Our findings suggest that CNF may be employed for an electrical interfacing of nerve cells and external devices.

We study the dewetting of liquid films deposited inside nonwettable and wettable capillaries. Two processes compete: (i) Rayleigh instability (i.e., amplification of thickness fluctuations) and (ii) dewetting by nucleation and growth of a dry zone limited by a rim collecting the liquid. At times shorter than the characteristic time τM of the growth of the Rayleigh instability, we expect two regimes: (i) annular rims and drying at constant velocities and (ii) columnar rims with drying velocities decreasing versus time. For wettable capillaries, in a certain regime of thin thicknesses, the Rayleigh instability is absent and dewetting is the only process to remove the film.