@article{sweet_oldham_parsons_2014, title={Atomic Layer Deposition of Metal Oxide Patterns on Nonwoven Fiber Mats using Localized Physical Compression}, volume={6}, ISSN={["1944-8252"]}, url={http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:000338184500045&KeyUID=WOS:000338184500045}, DOI={10.1021/am501582p}, abstractNote={Patterning is an essential part of many industrial processes from printing to semiconductor manufacturing. In this work, we demonstrate a new method to pattern and selectively coat nonwoven textiles by atomic layer deposition (ALD) using compressive mask patterning. A physical mask combined with mechanical compression allows lateral definition and fidelity of the ALD coating to be controlled. We produce features of several sizes on different nonwoven fiber materials and demonstrate the ability to limit diffusion effects to within <200 μm of the pattern edge. Lateral and vertical penetration of reactive growth species into nonwoven mats is investigated by plan-view and cross-sectional imaging. Vertical growth is also analyzed by imaging coating depth into fiber mat stacks. We develop a fully quantitative transport model that describes well the effect of fiber structure and mechanical compression on the extent of coating under the physical mask. This method could be implemented for high-volume patterning for applications including flexible electronics.}, number={12}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Sweet, William J., III and Oldham, Christopher J. and Parsons, Gregory N.}, year={2014}, month={Jun}, pages={9280–9289} }
 @article{kalanyan_oldham_sweet_parsons_2013, title={Highly Conductive and Flexible Nylon-6 Nonwoven Fiber Mats Formed using Tungsten Atomic Layer Deposition}, volume={5}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/AM401095R}, DOI={10.1021/am401095r}, abstractNote={Low-temperature vapor-phase tungsten atomic layer deposition (ALD) using WF6 and dilute silane (SiH4, 2% in Ar) can yield highly conductive coatings on nylon-6 microfiber mats, producing flexible and supple nonwovens with conductivity of ∼1000 S/cm. We find that an alumina nucleation layer, reactant exposure, and deposition temperature all influence the rate of W mass uptake on 3D fibers, and film growth rate is calibrated using high surface area anodic aluminum oxide. Transmission electron microscopy (TEM) reveals highly conformal tungsten coatings on nylon fibers with complex "winged" cross-section. Using reactant gas "hold" sequences during the ALD process, we conclude that reactant species can transport readily to reactive sites throughout the fiber mat, consistent with conformal uniform coverage observed by TEM. The conductivity of 1000 S/cm for the W-coated nylon is much larger than found in other conductive nonwovens. We also find that the nylon mats maintain 90% of their conductivity after being flexed around cylinders with radii as small as 0.3 cm. Metal ALD coatings on nonwovens make possible the solvent-free functionalization of textiles for electronic applications.}, number={11}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Kalanyan, Berç and Oldham, Christopher J. and Sweet, William J., III and Parsons, Gregory N.}, year={2013}, month={May}, pages={5253–5259} }