Nanofiber-base Refrigeration Alexandria Trevino and Bret Flanders - PowerPoint PPT Presentation

Nanofiber-base Refrigeration Alexandria Trevino and Bret Flanders Department of Physics Kansas State University

Thermoelectric Refrigeration Seebeck Effect T C T H ∆V

Directional Growth of polypyrrole and polythiophene wires Prem S. Thapa, Deok Jin Yu, James P. Wicksted, Jeffrey A. Hadwiger, Joseph N. Barisci, Ray H. Baughman, and Bret N. Flanders • Voltage-amplitude and frequency induces growth • Knobby structure 𝑚 𝐹𝑚𝑓𝑑𝑢𝑠𝑗𝑑𝑏𝑚 𝑑𝑝𝑜𝑒𝑣𝑑𝑢𝑗𝑤𝑗𝑢𝑧 = • 𝑆𝐵 Directional electrochemical nanowire assembly Thapa, P. S., Yu, D. J., Wicksted, J. P., Hadwiger, J. A., Barisci, J. N., Baughman, R. H., & Flanders, B. N. (2009). Directional growth of polypyrrole and polythiophene wires. Applied Physics Letters,94 (3), 033104. doi:10.1063/1.3072611

PEDOT:Heparin Growth Monomer Solution AU, WE AU, CE AU, WE Voltage AU, CE 40 μ m 20 μ m

Atomic Force Microscopy (AFM) 595 nm wire 1 µm 963 nm wire 5 μ m

50 40 L=74.66 𝜈 m L=52.70 𝜈 m 30 L=47.23 𝜈 m Count 20 10 0 400 600 800 1000 1200 Diameter (nm) ∆𝑊 − The voltage drop across R when I flows though it

100 𝜈 M Heparin content Length ( 𝛎 m) Resistance (M 𝞩 ) Diameter (nm) Conductivity (S cm^-1) Wire 1 64.03 993 1.07 0.770 Wire 2 64.30 830 0.988 1.20 Wire 3 62.96 964 0.813 1.06 Wire 4 44.55 973 0.858 0.698 Wire 5 57.15 960 1.13 0.700 Wire 6 49.81 622 1.26 1.30

10 𝜈 m Heparin content L=44.09 𝜈 m L=62.78 𝜈 m L=42.68 𝜈 m L=43.64 𝜈 m Length ( 𝛎 m) Resistance (M 𝞩 ) Diameter (nm) Conductivity (S cm^-1) Wire 1 42.68 1362 0.322 0.910

Heparin Conclusion • The electrical conductivity does not depend on diameter, resistance, and length. • We should see a consistency with the electrical conductivity of wires grown at the same conditions. Future Work PEDOT • Continue pursing decreasing the heparin content • Test the electrical conductivity of PEDOT: Heparin at different temperatures • Test the thermal conductivity • PEDOT: Tosylate

Acknowledgements • Bret Flanders • Krishna • Gobind • NSF • K-State • REU students

Questions? Length Diameter Resistance Conductivity ( 𝛎 m) (M 𝞩 ) (nm) (S cm^-1) L=74.66 𝜈 m L=52.70 𝜈 m Wire 1 42.68 1362 0.322 0.910 L=47.23 𝜈 m 5 μ m 50 L=44.09 𝜈 m L=62.78 𝜈 m 40 L=42.68 𝜈 m 30 Count L=43.64 𝜈 m Length Diameter Resistance Conductivity 20 ( 𝛎 m) (M 𝞩 ) (nm) (S cm^-1) 10 0 Wire 1 64.03 993 1.07 0.770 400 600 800 1000 1200 Diameter (nm) Wire 2 64.30 830 0.988 1.20 Wire 3 62.96 964 0.813 1.06 Wire 4 44.55 973 0.858 0.698 Wire 5 57.15 960 1.13 0.700 20 μ m 1 µm Wire 6 49.81 622 1.26 1.30