Compliant Array Research Articles

Mechanically Distinct Microtubule Arrays Determine the Length and Force Response of the Meiotic Spindle

The microtubule-based spindle is subjected to various mechanical forces during cell division. How the structure generates and responds to forces while maintaining overall integrity is unknown because we have a poor understanding of the relationship between filament architecture and mechanics. Here, to fill this gap, we combine microneedle-based quantitative micromanipulation with high-resolution imaging, simultaneously analyzing forces and local filament motility in the Xenopus meiotic spindle. We find that microtubules exhibit a compliant, fluid-like mechanical response at the middle of the spindle half, being distinct from those near the pole and the equator. A force altering spindle length induces filament sliding at this compliant array, where parallel microtubules predominate, without influencing equatorial antiparallel filament dynamics. Molecular perturbations suggest that kinesin-5 and dynein contribute to the spindle's local mechanical difference. Together, our data establish a link between spindle architecture and mechanics and uncover the mechanical design of this essential cytoskeletal assembly.

Material selection shape factors for compliant arrays in bending

Similar to the general class of metamaterials, compliant arrays (CAs) are engineered from an array of subelements that combine to produce a response that is typically not available from a flat panel made of a single material. As such, analysis and design of CA systems requires the integration of both the material and geometrical properties of the array. This paper proposes a convenient and efficient method of combining these essential elements using analytically derived shape factors for bending modes. The approach is validated experimentally, and used to demonstrate large regions of previously inaccessible property combinations in material selection charts that become attainable using carefully design CAs.

The IRIDIUM main mission antenna concept

The design of a novel phase array panel that provides the L-band satellite to ground links for the IRIDIUM global communications system is presented. Key components and aspects of this phase array antenna are discussed including the beamforming architecture, radiated intermodulation products, the patch radiators, and the T/R module. The strategy for minimizing DC power consumption over a large range of multicarrier RF output power is described. Finally, test results showing compliant array operation are summarized.

The IRIDIUM/sup R/ main mission antenna concept

The design of a novel phased array panel that provides the L-band satellite to ground links for the IRIDIUM global communications system is presented. Key components and aspects of this phased array antenna are discussed, including the beamforming architecture, radiated intermodulation products, the patch radiators, and the T/R module. The strategy for minimizing DC power consumption over a large range of multicarrier rf output power is described. Finally, test results showing compliant array operation are summarized.