Patterning, conducting polymer

Halik and coworkers subsequently extended this process to pattern conducting polymer electrodes, such as poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT-PSS) [11]. In this process, PEDOT-PSS is uniformly coated on a substrate that has prepattemed photoresist. The PEDOT-PSS-coated substrate is then immersed in acetone to swell the photoresist underneath the... 

We are combining the selective deposition of polypyrrole and polyaniline on hydrophilic/hydrophobic surfaces as described in the preceeding section with the recent microcontact printing technique (18-20) to produce patterned conducting polymer films which we have demonstrated can be used in PDLC display-type devices. 

Massari, A. M. Stevenson, K. J. Hupp, J. T. Development and application of patterned conducting polymer thin films as chemoresponsive and electrochemically responsive optical diffraction gratings. J. Electroanal. Chem. 2001, 500, 185-191. 

A completely different approach to patterning conducting polymers involves the use of photosensitive oxidants [86,87]. In this process, a photosensitive oxidant is mixed with a host polymer such as poly (vinyl chloride), poly(vinyl alcohol), or polycarbonate. The composite is applied to a substrate. Upon irradiation of the film, the oxidant in the exposed regions is made inactive, whereas in the unexposed regions the oxidant can still induce polymerization of appropriate monomers. After exposure, the latent image is exposed to a monomer such as pyrrole either in solution or in the vapor state. Polymerization occurs only in the nonexposed areas where the oxidant is still active. In this fashion, patterns are delineated that consist of conducting composite materials. Some photosensitive oxidants include Fe(III) salts such as iron trichloride and ferrioxalate. Upon exposure, the Fe(III) is converted to Fe(II), which does not induce oxidative polymerization [86,87]. 

It should also be pointed out that the imageable conducting polymers described in the previous section would be quite applicable to metallization. A conducting polymer could be applied to the circuit board surface and directly imaged, thereby eliminating an additional photoresist process. Electroplating can then occur selectively on the patterned conducting polymer. 

M. Nishizawa, Y. Miwa, T. Matsue, and I. Uchida, Surface pretreatment for electrochemical fabrication of ultrathin patterned conducting polymers. J. Elec-trochem. Soc. 74(7(6) 1650 (1993). 

In this paper we report the selective assembly of a conducting polymer onto a prefabricated patterned template assisted by DC electric field. More importantly, we have demonstrated the patterned conducting polymers can be transferred onto a flexible and insulating polymeric substrate by compression molding. 

Here, electric fields caused the deposition of polyaniline on the patterned template to occur rapidly in one-step and avoided complicated chemistry methods, such as the template polymerization of a conductive polymer and functionalization of the substrate surface. In addition, the use of an external electric field provides a combination of advantages including simplicity, high rates, easy control and prompt response to the ON-OFF cycles of the applied electric field, which may not otherwise be achieved through inherent interactions. It meets the requirements of a low cost, high volume method to pattern conducting polymers for the production of miniaturized complex features needed by industry. 

In conclusion, we have demonstrated a simple and rapid method to pattern conductive polymers on a flexible and insulated substrate. A patterned conductive polymer, PANi, was assembled on a patterned template through the use of an electric field and an insulated template. It was found that the deposition of PANi on the template depends on the deposition time and applied electric field strength. The employment of an electric field avoids complicated chemistry methods, accelerates the assembly process, offers easy control by ON-OFF cycles, and provides the possibility to achieve high throughput. The addition of an insulating silicon dioxide layer on the template provides the ability to prepare patterned PANi, rather than a continuous film. After assembly of PANi onto the template, we have demonstrated that patterned PANi can be transferred onto polymer substrates by compression molding. The transfer by compression molding was not complete due to the low mobility of PU molecules. 

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