Abstract: A propeller according to an embodiment includes a hub and a series of blades extending outward from the hub. Each blade of the series of blades includes a core and a skin covering the core. The core may be formed of a ceramic first material and the skin is formed of a second material different than the ceramic first material. The ceramic first material of the core may be ceramic Si3N4 (silicon nitride), yttria-toughened zirconia ceramic, or alumina-zirconia ceramic, and the second material of the skin may be a polymer. The polymer skin is configured to function as a shock absorber protecting the ceramic core, and the ceramic core is configured to provide rigidity to maintain the shape of the propeller blades under aerodynamic loading, which enables improved aerodynamic efficiency and reduced noise generation.

Abstract: Molds for making cell aggregation devices include upper and lower surfaces. Methods of aggregating cells include depositing cells on in a seeding chamber, incubating the cells and removing aggregated cells. Devices for encapsulating aggregates of cells include biocompatible, bio-sustainable substrates compartments and a coating of a biocompatible, bio-sustainable polymer that completely surrounds the substrate and cell-encapsulating compartments.

Abstract: Provided are assays and methods for creating proto-tissues from aggregates of cells. The invention concerns assays and methods useful in tissue engineering and reconstruction techniques, specifically in the formation of macrotissues from microtissues using microtissue pre-culture time as a controlling parameter.

Abstract: Provided are assays and methods for creating proto-tissues from aggregates of cells. The invention concerns assays and methods useful in tissue engineering and reconstruction techniques, specifically in the formation of macrotissues from microtissues using microtissue pre-culture time as a controlling parameter.

Abstract: The invention is a cell aggregation device comprising a hydrogel substrate having at least one, preferably a plurality, of cell-repellant compartments recessed into the uppermost surface. Each compartment is composed of an upper cell suspension seeding chamber having an open uppermost portion and a bottom portion, and one, or more than one, lower cell aggregation recess connected to the bottom portion of the upper cell suspension seeding chamber by a port. The diameter of the port may be fully contiguous with the walls of the chambers and walls of the recesses, or the diameter of the port may be more narrow than the walls of the chamber but fully contiguous with the walls of the recesses or more narrow than both the walls of the chamber and the walls of the recesses. The upper cell suspension seeding chambers are formed and positioned to funnel the cells into the lower cell aggregation recesses through gravitational force.