This paper describes the first thermoelectric devices based on the V-VI-compounds Bi/sub 2/Te/sub 3/ and (Bi,Sb)/sub 2/Te/sub 3/ which can be manufactured by means of regular thin film technology in combination with microsystem technology. Fabrication concept, material deposition for some 10-/spl mu/m-thick layers and the properties of the deposited thermoelectric materials will be reported. First device properties for Peltier-coolers and thermogenerators will be shown as well as investigations on long term and cycling stability. Data on metal/semiconductor contact resistance were extracted form device data. Device characteristics like response time for a Peltier-cooler and power output for a thermogenerator will be compared to commercial devices

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A mechanical system consisting of a movable base and an object (rigid body) connected to the base by means of a two degree of freedom gimbal with mutually perpendicular axes is considered. The possibility to eliminate the projection of the apparent acceleration of a given object point on the plane perpendicular to an object fixed axis by controlling the rotation of the gimbal frames is investi gated. The apparent acceleration of a given object point is the difference between the absolute accel eration vector and the gravitational acceleration vector at this point. Sufficient conditions under which this goal is attainable in principle are formulated. Equations governing the rotation of the gimbal frames are derived. This problem is related to the development of control systems for gravity sensitive technologies in spacecraft.

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This paper contains a survey of some results related to the theory of strongly inhomogeneous media and also new results on the description of finite volume eigen-oscillation spectra whose dynamics is described by effective (averaged) models of such media.

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Swimming bacteria successfully colonize complex non-Newtonian environments exemplified by viscoelastic media and even liquid crystals. While there is a significant body of research on microswimmer motility in viscoelastic liquids, the field still lacks clarity. This paper studies how individual microswimmers (e.g., bacteria) interact in a mucus-like environment modeled by a visco-elastic liquid crystal. We have found that an individual swimmer moves faster along the same track after the direction reversal, in faithful agreement with the experiment. This behavior is attributed to the formation of the transient tunnel due to the visco-elastic medium memory. We observed that the aft swimmer has a higher velocity for two swimmers along the same track and catches up with the leading swimmer. Multiple swimmers launched at different angles form a “train”: after some transient, the following swimmers repeat the path of the “leader”. Our results shed light on bacteria penetration in mucus and colonization of heterogeneous liquid environments.