Materials and Processing at the Nanometer Scale

Abstract

Abstract : Researchers supported by the DoD MURI on Materials & Processing at the Nanometer Scale (administered by AFOSR) have pioneered the use of nanoscale 'dendrimers' or 'tree-like branched molecular structures with each limb designed for a special function' to achieve electronic isolation and directed energy/charge transport. These novel dendrimer materials have been used to develop improved electro-optic modulator materials, light harvesting and optical amplifier materials, high-density electronic memory materials, light emitting diode materials, and two-photon lasing materials. Incorporation of electro-optic organic chromophore into the core of dendrimer materials eliminates quenching of macroscopic electro-optic activity by intermolecular (chromophore) electrostatic interactions. Other advances involving nanoscale materials include the first demonstration (with Allied Signal Corporation and later Honeywell) of single wall carbon nanotube actuators. Polymer nanospheres have been used to demonstrate high-density erasable optical memories and nanoscale chemical reactors crucial for improving the efficiency of fuel cells. Polymer microspheres have also been used as templates for chemical synthesis and such chemical machining has been used to achieve visible wavelength photonic bandgap materials. Advances have been made in the fabricating of phase-separating block copolymers. Inorganic/organic nanocomposites have been used to fabricate high-density optical memories (including holographic and two-photon memories), organic lasers, and sensor protection materials.