Natural wood fibers are an earth-abundant, renewable, biodegradable, and non-petroleum based material that offers unique properties. Green electronics are steadily gaining research and commercial interest due to the promise of creating flexible, lightweight, cost efficient, renewable, and biocompatible devices. Nanopaper made from cellulose nanofibers possesses tunable optical properties, mechanical strength, and small surface roughness enabling many types of electronics that were not previously possible using regular paper or plastic substrates. Additionally, the transition from rigid glass to flexible paper substrates enables the creation of flexible and transparent devices that can be produced quickly using established roll-to-roll manufacturing methods. Lowering the cost and improving the performance of devices are essential for making renewable energy feasible for everyday applications. Various nanopaper electronics are demonstrated in our group, including transistors, organic light emitting diodes (OLEDs), touch screens, solar cells, and antennae.

With the cellulose fiber network as a host, we impregnate other functional materials, like boron nitride and Fe3O4, to give the paper good thermal conductivity and magnetic properties. Meanwhile, with strong nanocellulose as building blocks, we fabricated multifunctional fibers with high mechanical strength and excellent electrical conductivity for the application in energy storage, smart textiles, and low density materials in space. The manufacturing of 2D paper and 1D fibers based on earth abundant material have the potential to expand green electronics as well as galvanize a new future for renewable multifunctional materials.

References:

Zhu, H., Li, Y., Fang, Z., Xu, J., Wan, J., Dai, J., Yang, B., Hu, L. Highly Thermally Conductive Films with Percolative Layered Boron Nitride Nanosheets. ACS Nano. 2014.

Zhu, H., Narakathu, B., Fang, Z., Aijazi, A., Joyce, M., Atashbar, M., Hu. L. Antenna on Shape-Stable Transparent Nanopaper. Nanoscale. accepted.

Zhu, H.,§ Fang, Z.,§ Preston, C., Li, Y., Hu, L.*. Transparent Paper Fabrications, Properties, and Device Applications. Energy and Environmental Science. 2013, 269 - 287.

Zhu, H., § Fang, Z., § Ha, D., Preston, C., Chen, Q., Lacey, S., Li, Y., Han, X., Lee, S., Chen, G., Chai, X., Munday, J., Hu, L.*. Paper with Ultra-High Transparency and Ultra-High Haze for Solar Cells. Nano Letters, accepted, 2013.

Zhu, H., Xiao, Z., Liu, D., Li, Y., Weadock, N.J., Fang, Z., Huang, J., Hu, L. *. Biodegradable Transparent Substrates for Flexible Organic-Light-Emitting Diodes, Energy and Environmental Science 2013, 6, 2105-2111.

Zhu, H., Parvinian, S., Preston, C., Vaaland, O., Ruan, Z., Hu, L.*. Transparent Nanopaper with Tailored Optical Properties, Nanoscale, 2013, 5, 3787-3792.

Zhu, H.§, Huang, J.§, Chen, Y., Preston, C., Rohrbach, K., Cumings, J., Hu, L.*. Highly Transparent and FlexibleNanopaper Transistors, ACS Nano, 2013, 7 (3), 2106-2133.

Hongli Zhu

University of Maryland

Appearances