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This paper presents results of a preliminary study of feasibility for the application of electroactive polymer (EAP) based actuators to a robotic locomotion system, intended by the European Space Agency (ESA) to operate on the surface of Mars. The system is conceived as an elastic spherical rover, exploiting wind propulsion for surface motion, while adopting an active mechanism for vertical jumping over obstacles. The use of polymeric electromechanical devices is envisaged in order to provide actuation to such a jumping mechanism. Among the available EAP technologies, new contractile linear actuators based on dielectric elastomers are proposed in this study as suitable devices and two potential solutions concerning their use are designed, modeled, and evaluated via numerical simulations. The best solution reveals interesting simulated performances, enabling jumping of obstacle heights corresponding to more than 7% of the diameter of the rover.

We have tried to confirm the sign inversion of the photocarrier in regiorandom poly(3-octadecylthiophene), PAT18, by means of the time-of-flight (TOF) method. It was found that the hole mobility decreases with increasing temperature. At the temperature near the solid-liquid phase transition, the hole mobility decreases drastically, and eventually the melting temperature, it was impossible to evaluate the hole mobility from noisy transient photocurrent. On the other hand, transient photocurrents based on electron transport are observed above the melting point. The negative carrier mobility was evaluated in the range from [10.sup.-6] to [10.sup.-5] [cm.sup.2]/Vs, which is comparably the hole mobility at the solid state. Moreover, the electrical conductivity changes drastically at the instant of the solid-liquid phase transition, and transport in the liquid state was not influenced remarkably by applied hydrostatic pressure, which suggests electronic transport and not ionic transport. These facts suggest that the same mechanism, for example interchain hopping limits carrier transport, and the negative carrier is electron. This unique phenomenon is interpreted as modulation of electronic energy state caused by conformational change of the main chain. Index Terms--Conducting polymers, poly(3-alkylthiophene), time-of-flight method, solid-liquid phase transition, sign inversion of photocarriers.

An investigation has been undertaken into the thermal instability of electroactive, cellular polypropylene, in particular concentrating on the interaction between mechanical and electrical properties. A range of mechanical and electrical techniques have been applied including, dynamic mechanical analysis (DMA), thermo mechanical analysis (TMA), thermally stimulated currents (TSC) and admittance spectroscopy. Evidence is presented which indicates that the initial stages of a TSC spectrum is dominated by thickness changes in the foam. Changes in mechanical dimensions correlate well with temperature-induced changes in resonator parameters. Index Terms--Piezoelectricity, electrets, electroactive polymers, cellular polypropylene.

Sound isolation has been achieved using a piezoelectric polymer film connected to a negative capacitance feedback circuit. A curved PVDF film was located in the middle of an acoustic tube and the transmission loss of sound through the film was determined in the audio frequency range. At any chosen frequency, the complete isolation of sound was achieved by adjusting the feedback, i.e. the complex capacitance of the circuit was matched precisely to that of the film. Index Terms--Sound isolation, transmission loss, piezoelectric polymer film, negative capacitance circuit.

Making use of defects modification to P(VDF-TrFE) via either high energy electron irradiation treatment or copolymerizing VDF-TrFE with a small amount of chlorinated monomer to form a random terpolymer, we demonstrate that high electromechanical responses can be realized in P(VDF-TrFE) based polymers. It will be shown that in the stretched and irradiated 68/32 mol% copolymer, a transverse strain of 4.5% and a transverse electromechanical coupling factor [k.sub.31] of 0.65 can be induced under a field of 85 MV/m. In addition, the irradiated copolymer also exhibits a high elastic energy density, ~ 1 J/c[m.sup.3]. For PVDF based terpolymers such as P(VDF-TrFE-CFE) terpolymer (CFE: chiorofluoroethylene), an electrostrictive strain of more than 7% can be obtained. To elucidate the microstructure changes due to the defects modification in P(VDF-TrFE) based polymers, synchrotron X-ray measurement was carried out on the irradiated copolymers and the results show that, the irradiation converts the polar-phase into a non-polar phase. In addition, X-ray date show that the polar-phase can be induced, at the expense of the non-polar phase, by external fields, confirming that the field induced conformation change is responsible for the observed high electromechanical responses. Although the modified PVDF based polymer exhibits the highest room temperature dielectric constant (60 versus below 10), it is still far below those in the inorganic materials. Experimental results show that by using delocalized electrons in conjugated bonds an all-organic composite with a dielectric constant more than 400 can be achieved. As a result, a strain of near 2% with an elastic energy density higher than 0.1 J/c[m.sup.3] can be induced under a low applied field of 13 V/[micro]m. The strain is proportional to the applied field and the composite has an elastic modulus near 1 GPa. Index Terms--Electroactive polymers, relaxor-ferroelectric polymers, high dielectric constant polymers, electrostriction, field effect actuators.

Research is presented describing the development of an array based on a 16 x 16 PVDF ceramic integrated sensor.

A conducting polymer with highly extended conjugated bonds in its main chain becomes fusible and also soluble in common solvents after the introduction of long side chains, such as alkyl, as a substituent. Because these liquid conducting polymers and oligomers have much smaller band gaps than those of conventional organic liquids, they exhibit relatively high electrical conductivity and also interact with visible light. Therefore, these liquid conducting polymers can be used effectively for fundamental research to clarify the electronic state and transport processes in dielectric liquids. Novel anomalies in electrical conductivity, photoconductivity and luminescence also have been observed in these liquids, and are discussed in terms of the fluctuation of electronic band gap and the interchain interaction, which depends on alkyl side chain length and on its conformation, and therefore on temperature. The unique applications of these liquid conducting polymers and solutions are also discussed. Characteristics of the interface between conducting polymer and dielectric liquids are also found and discussed in terms of electron scavenging of C[O.sub.2] in liquid and C[O.sub.2] fixation.

Krishna Naishadham and Prasad K. Kadaba's research on the use of polyacetylene and polybutylene terephthalate as microwave absorbers and electromagnetic shields contains discrepancies between the computed results and assumptions made. An example is the shielding effectiveness for which an assumption of frequency invariance was made. To correct this, the authors present their recalculations.

Studies of lasing and stimulated emission produced by optical pulsed excitation pi-conjugated, or conducting, polymers are presented.