Positron emission mammography ("PEM") is a breast imaging modality that typically involves the administration of
relatively high doses of radiotracer. In order to reduce tracer costs and consider PEM for global screening applications, it
would be helpful to reduce the required amount of administered radiotracer so that patient dose would be comparable to
conventional x-ray mammograms.
We performed GATE Monte Carlo investigations of several possible camera configurations. Increasing the detector
thickness from 10 to 30 mm, increasing the camera surface area from 5×20cm<sup>2</sup> to 20×20cm<sup>2</sup>, and applying depth-ofinteraction information to increase the acceptance angle, increased the overall efficiency to radiation emitted from a breast cancer by a factor of 24 as compared to existing commercial systems.
Cell-based sensors are being developed to harness the specificity and sensitivity of biological systems for sensing
applications, from odor detection to pathogen classification. These integrated systems consist of CMOS chips
containing sensors and circuitry onto which microstructures have been fabricated to transport, contain, and nurture the
cells. The structures for confining the cells are micro-vials that can be opened and closed using polypyrrole bilayer
actuators. The system integration issues and advances involved in the fabrication and operation of the actuators are
A compliant electrode material is presented that was inspired by the electroding process used to manufacture ionic polymer-metal composites (IPMCs). However, instead of an ion-exchange membrane, a UV-curable acrylated urethane elastomer is employed. The electrode material consists of the UV-curable elastomer (Loctite 3108) loaded with tetraammineplatinum(II) chloride salt particles through physical mixing and homogenization. The composite material is made conductive by immersion in a reducing agent, sodium borohydride, which reduces the salt to platinum metal on the surface of the elastomer film. Because the noble metal is mixed into the elastomer precursor as a salt, the amount of UV light absorbed by the precursor is not significantly reduced, and the composite loses little photopatternability. As a result meso-scale electrodes of varying geometries can be formed by exposing the precursor/salt mixture through a mask. The materials are mechanically and electrically characterized. The percolation threshold of the composite is estimated to be 9 vol. % platinum salt, above which the compliant electrode material exhibits a maximum conductivity of 1 S/cm. The composite maintains its electrical conductivity under axial tensile strains of up to 40%.
We present the use of electroactive polymer actuators as components of a biolab-on-a-chip, which has potential applications in cell-based sensing. This technology takes full advantage of the properties of polypyrrole actuators as well as the wide range of CMOS sensors that can be created. System integration becomes an important issue when developing real applications of EAP technologies. The requirements of the application and the constraints imposed by the various components must be considered in the context of the whole system, along with any opportunities that present themselves. In this paper, we discuss some of these challenges, including actuator design, the use of complementary actuation techniques, miniaturization, and packaging.