Motile porcine sperms adhere to hydrophilic materials such as glass and plastics. The adsorption of sperms to a hydrophobic poly(dimethylsiloxane) (PDMS) membrane is less compared with that to glass. We investigated the linear velocity (LV) and amplitude of lateral head displacement (ALHD) of motile porcine sperm on glass and PDMS preparations using computer-assisted sperm analysis (CASA). Sign...

PURPOSE The purpose of this study was to measure spectrophotometrically the color stability of pigmented A-2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5-year period of microwave sterilization. MATERIALS AND METHODS A-2186 silicone elastomer opacified with titanium white dry eart...

Dielectric elastomer actuators (DEAs) show promise for robotic and mechatronic applications. However, to date, these actuators have experienced high rates of failure that have prevented their practical application. Here, large scale modes of failure of DEAs and their performance limits are studied. The objective is to provide design guidelines and bound the performance of DEAs that avoid failur...

STATEMENT OF PROBLEM The success of most non-implant-retained extraoral prostheses depends on retention derived from skin adhesives. Part 1 of this study found that Skin-Prep Protective Dressing improved the retentive properties of adhesives and that Secure(2) Medical Adhesive was stronger than Epithane-3. Part 2 investigates the application of a second layer of adhesive to the prosthesis, whic...

The effect of interfacial friction on adhesion was studied by using a model system, in which a thin strip of silicone elastomer was peeled from a PDMS (poly(dimethylsiloxane)) treated glass slide. The fluorescent particle tracking method revealed that the elastomer stretches and slides on glass well before the crack faces open up. Interfacial energy dissipation due to friction, which is the pro...

We review in these lecture notes some of our recent work on modelling the response of nematic elastomers to applied mechanical loads and/or to electric fields, both in the static and in the dynamic regime. Our aim is to compare theoretical results based on mathematical analysis and on numerical simulations with the available experimental evidence, in order to examine critically the various rece...

AIM AND OBJECTIVE To compare and evaluate the effect of ultraviolet (UV) stabilizers (Chimassorb 81 and Uvinul 5050) on the color change of pigmented elastomer. MATERIALS AND METHODS Two pigments - Red (P112 Brilliant Red) and Yellow (P106 Yellow) and two UV stabilizers Chimassorb 81 and Uvinul 5050 were studied. A total of six groups of 10 samples each were fabricated using a combination of ...

We study the low-frequency, long-wavelength dynamics of soft and semi-soft nematic elastomers using two different but related dynamic theories. Our first formulation describes the pure hydrodynamic behavior of nematic elastomers in which the nematic director has relaxed to its equilibrium value in the presence of strain. We find that the sound-modes structure for soft elastomers is identical to...

BACKGROUND Product adherence is a pivotal issue in the development of effective vaginal microbicides to reduce sexual transmission of HIV. To date, the six Phase III studies of vaginal gel products have relied primarily on self-reporting of adherence. Accurate and reliable methods for monitoring user adherence to microbicide-releasing vaginal rings have yet to be established. METHODS A silico...

Fixing a prestretched dielectric elastomer actuator (DEA) on a flexible frame allows transformation of the intrinsic in-plane area expansion of DEAs into complex three-dimensional (3D) structures whose shape is determined by a configuration that minimizes the elastic energy of the actuator and the bending energy of the frame. These stuctures can then unfold upon the application of a voltage. Th...