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Current Cool Picture
 
Conducting polymer (PPy) microstructures
Intoduction
We present the three-dimensional (3D) growth of polypyrrole (PPy) microstructures with high aspect ratios (HAR) by a localized electropolymerization. The radicals formed by an oxidation of Py monomer is localized on the targeting area due to a confinement of electric field, forming a PPy structure. We found that a reversal point at which the relative field strengths of Ec (center of the grown structure) and Ee (edge) are reversed is a critical factor in determining the growth characteristic of the 3D PPy structure. A porous structure with open and closed pores is produced below the reversal point by the hydrogen bubble trapping in a gap between the microelectrode and the grown structure. Above the reversal point, a structure with dense and uniform features is obtained by a steady supply of monomer in the gap without bubble trapping.
Some pictures of our experiments

PPy microstructures fabricated by no-contact growth mode of LECD
(a) FESEM images of free-standing PPy HAR microstructures with dense and smooth morphology. The images show (a) a wirelike straight structure with aspect ratio ) 70, (b) a zigzag structure, and (c) a complex structure corresponding to the letters “XIC”.
 
 
Pohang University of Science & Techology San 31, Hyojadong, Pohang 790-784, Republic of Korea   
 
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