Progress in preparation, processing and applications of polyaniline

An electrosurgical medical device and method for creating thermal welds in engaged tissue. In one embodiment, at least one jaw of the instrument defines a tissue engagement plane carrying a conductive-resistive matrix of a conductively-doped non-conductive elastomer. The engagement surface portions thus can be described as a positive temperature coefficient material that has a unique selected decreased electrical conductance at each selected increased temperature thereof over a targeted treatment range. The conductive-resistive matrix can be engineered to bracket a targeted thermal treatment range, for example about 60° C. to 80° C., at which tissue welding can be accomplished. In one mode of operation, the engagement plane will automatically modulate and spatially localize ohmic heating within the engaged tissue from Rf energy application—across micron-scale portions of the engagement surface. In another mode of operation, a conductive-resistive matrix can induce a “wave” of Rf energy density to sweep across the tissue to thereby weld tissue.

Electrosurgical instrument and method of use

Conducting polymers prepared by oxidative polymerization: polyaniline

A method of forming an electronic circuit component using the technique of drop on demand printing to deposit droplets of deposition material, said method comprising depositing a plurality of droplets on a surface to form a patterned electronic device comprising multiple discrete portions.

Method of forming an electronic device

Various embodiments provide compositions that exhibit positive temperature coefficient of resistance (PTCR) properties for use in thermal interactions with tissue—including thermal sensing and I2R current-limiting interactions. Embodiments also provide tissue-engaging surfaces having PTCR materials that provide very fast switching times between low resistance and high, current-limiting resistance. One embodiment provides a matrix for an electrosurgical energy delivery surface comprising a PTCR material and a heat exchange material disposed within an interior of the matrix. The PTCR material has a substantially conductive state and a substantially non-conductive state. The heat exchange material has a structure configured to have an omni-directional thermal diffusivity for exchanging heat with the PTCR material to cause rapid switching of the PTCR material between the conductive state and non-conductive state. Preferably, the structure comprises a graphite foam having an open cell configuration. The matrix can be carried by tissue contacting surfaces of various electrosurgical devices.

Surgical sealing surfaces and methods of use

Transparent conductive coatings

A polymer blend according to the invention of the type including an intrinsically conductive polymer disbursed in a matrix selected from thermoplastic polymers, monomers, polymerizable precursors and combinations thereof is improved by an amount of a non-polymeric polar additive having a boiling point greater than about 100° C. at 760 mm pressure and greater than the processing temperature of the matrix polymer incorporated in the polymer blend, in an amount sufficient to impart an electrical conductivity to the blend which is greater than that of the blend without the non-polymeric polar additive. A blend according to the invention includes a matrix material selected from thermoplastic polymers, monomers and polymer precursors and combinations thereof, and an intrinsically conductive polymer and a non-polymeric highly polar additive, disbursed into a polymer blend and having a conductivity of greater than about 2.5 S/cm. A composition according to the invention includes a precursor selected from polymers and polymerizable monomers, an intrinsically conductive polymer with a conductivity of about 1 to 5 S/cm and a non-polymeric polar additive having a conductivity of greater than that of the blend resulting in a blend having a conductivity greater than about 2 to 5 s/cm. A blend having thermo and conductive stability includes an intrinsically conductive polymer, an insulating thermoplastic polymer, an insulating thermoplastic polymer and an ester-free plasticizer which is thermally stable to at least about 240° C., the blend having a conductivity of greater than 10 -2 S/cm. A method for preparing such compositions and blends is also provided.

Highly conductive polymer blends with intrinsically conductive polymers

An electrically conductive coating composition includes an intrinsically conductive polymer dispersed in a film-forming thermoplastic matrix. The coating composition also includes at least one organic solvent capable of dissolving the dispersion. A method according to the invention includes the steps of preparing a dispersion of an intrinsically conductive polymer in a film-forming thermoplastic matrix. The method also includes the steps of dissolving the dispersion in an organic solvent and forming a film from the dissolved dispersion.

John C. Campbell

Papers

Transparent conductive coatings

Highly conductive polymer blends with intrinsically conductive polymers

Electrically conductive coating compositions and method for the preparation thereof