Direct Measurement of Mass Transport in Actuation of Conducting Polymers Nanotubes.

Nanostructured Conducting polymer (CP) actuators are promising materials for biomedical applications such as drug release systems. However, understanding the actuation behavior at the nano-scale has not yet been explored. In this work, poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(pyrrole) (PPy) nanotubes doped with a large counter ion (i.

Tunable nanostructured conducting polymers for neural interface applications.

Advancement in the development of traditional metallic-based implantable electrodes for neural interfacing has reached a plateau in recent years in terms of their ability to provide safe, long-term, and high resolution stimulation and/or recording. The reduction of electrode size enables higher selectivity through increased electrodes per implant device; however, it also results in lower sensitivity at electrode-tissue interfaces. This limitation can be addressed through the utilization of conducting polymer (CP) coatings, which increase the effective surface area.

Conducting polymer microcontainers for biomedical applications.

Advancement in the development of metallic-based implantable micro-scale bioelectronics has been limited by low signal to noise ratios and low charge injection at electrode-tissue interfaces. Further, implantable electrodes lose their long-term functionality because of unfavorable reactive tissue responses. Thus, substantial incentive exists to produce bioelectronics capable of delivering therapeutic compounds while improving electrical performance.

Conducting Polymer Microcups for Organic Bioelectronics and Drug Delivery Applications.

An ideal neural device enables long-term, sensitive, and selective communication with the nervous system. To accomplish this task, the material interface should mimic the biophysical and the biochemical properties of neural tissue. By contrast, microfabricated neural probes utilize hard metallic conductors, which hinder their long-term performance because these materials are not intrinsically similar to soft neural tissue.

Graphical analysis of mammalian cell adhesion in vitro.

Short-term (<2h) cell adhesion kinetics of 3 different mammalian cell types: MDCK (epithelioid), MC3T3-E1 (osteoblastic), and MDA-MB-231 (cancerous) on 7 different substratum surface chemistries spanning the experimentally-observable range of water wettability (surface energy) are graphically analyzed to qualitatively elucidate commonalities and differences among cell/surface/suspending media combinations. We find that short-term mammalian cell attachment/adhesion in vitro correlates with substratum surface energy as measured by water adhesion tension, τ≡γcosθ, where γ is water liquid-vapor interfacial energy (72.8   mJ/m) and cosθ is the cosine of the advancing contact angle subtended by a water droplet on the substratum surface.

Mammalian cell-adhesion kinetics measured by suspension depletion.

Mammalian cell-adhesion kinetics is measured by counting the number of cells lost from suspension due to adhesion to planar or particulate substrata as a function of time rather than by the counting of adherent cells that is widely applied in the literature. A simple statistical model shows that this "suspension-depletion" method is most accurate at low cell counts in the critical early stage of cell adhesion that is diagnostic of forces in close proximity between cell and substratum responsible for cell adhesion. Furthermore, suspension depletion avoids experimental artifacts associated with substratum rinsing and the removal of cells from the substratum using enzymatic and/or mechanical methods.