Abstract: A dynamic DNA model and DNA model kit that is based on the atomic coordinates of double-stranded DNA, but can be easily untwisted to form a flattened 2-D ladder structure. Once untwisted, the two strands of DNA can be easily “unzipped” to create single-stranded DNA templates that can be used to demonstrate the processes of DNA replication and transcription. The model and kit include two joints that allow the DNA model to be dynamically transformed from its helical arrangement into a straight ladder-like arrangement, with parallel base pairs and anti-parallel “backbones.” One joint is a pin joint, having rotation about one axis, and translation along that axis. The second joint can be a “compound” joint having multiple degrees of freedom at different points; or, it can be simplified to a single rotation axis with a separate translation axis.

Abstract: An actuation system for a joint includes an actuator having a piston, an articulating element coupled to the actuator that is driven by the piston to match a gait cycle of an appendage, an energy source engaged with the piston that energizes working fluid within the actuator to drive the piston and generate exhaust gas, a plurality of valves coupled to the actuator, and an exhaust gas holding element coupled to the actuator that is sized to hold a volume of the exhaust gas contained within the actuator.

Abstract: A method of casting including coating at least a portion of a mold with a non-porous coating, placing the mold in a chamber capable of inducing pressure, and applying pressure to the chamber to press material into a cavity in the mold. Another method of casting including coating at least a portion of a mold with a non-porous coating, placing a first fill tube in a material, applying a vacuum to a second fill tube to establish a vacuum within the non-porous coating, and allowing atmospheric pressure to inject the material into the mold without placing the mold in a chamber capable of inducing pressure.

Abstract: A molecular modeling kit including a three-dimensional body providing a physical representation of at least one atom. The three-dimensional body can define a cavity and include a self-reorienting magnet at least partially disposed in the cavity. The magnet can be configured to realign relative to the cavity when in proximity with a second magnet such that magnetic poles of the self-reorienting magnet and the second magnet are aligned for attraction. The second magnet can be external to the three-dimensional body.

Abstract: Three-dimensional models of molecules, including proteins, and molecular model construction kits, including an alpha helix construction kit, a beta sheet construction kit, and a nucleic acid construction kit. The three-dimensional models of molecules include one or more elongated tubular strands representing alpha carbons and the bonds between the alpha carbons. The alpha helix and beta sheet construction kits include amino acid backbone units, hydrogen bond units, and side chain units. The nucleic acid construction kits include base units, hydrogen bond units, sugar units, and phosphate units.

Abstract: A three dimensional object having a first one-piece build style lattice including a plurality of substantially uniform build style units and a second one-piece build style lattice integrally formed with and interlaced with the first lattice, the second lattice including a plurality of substantially uniform build style units.

Abstract: A method for forming a three dimensional object, the method including the steps of generating a digital representation of the object, generating a digital representation of a build style lattice having a substantially uniform, conformal tetrahedron structure, overlaying the respective representations of the object and the build style, intersecting the overlaid representations to generate a digital representation of the object incorporating the build style; and fabricating the digital representation of the object incorporating the build style by solid free form fabrication.

Abstract: A three dimensional object having a first one-piece build style lattice including a plurality of substantially uniform build style units and a second one-piece build style lattice integrally formed with and interlaced with the first lattice, the second lattice including a plurality of substantially uniform build style units.

Abstract: A solid free form model of a complex structure, such as a molecular structure, and a method of making such a model. The model includes a first elongated strand extending along a first path corresponding to the locations of selected elements to represented, a second elongated strand extending along a second path spaced from the first path and a connecting leg extending between the first and second strands along a path corresponding to the vector along which a force, such as a hydrogen bond, acts on the modeled elements.

Abstract: Three-dimensional models of molecules, including proteins, and molecular model construction kits, including an alpha helix construction kit, a beta sheet construction kit, and a nucleic acid construction kit. The three-dimensional models of molecules include one or more elongated tubular strands representing alpha carbons and the bonds between the alpha carbons. The alpha helix and beta sheet construction kits include amino acid backbone units, hydrogen bond units, and side chain units. The nucleic acid construction kits include base units, hydrogen bond units, sugar units, and phosphate units.

Abstract: A method for forming a three dimensional object, the method including the steps of generating a digital representation of the object, generating a digital representation of a build style lattice having a substantially uniform, conformal tetrahedron structure, overlaying the respective representations of the object and the build style, intersecting the overlaid representations to generate a digital representation of the object incorporating the build style; and fabricating the digital representation of the object incorporating the build style by solid free form fabrication.

Abstract: A method for forming a three dimensional object, the method comprising the steps of generating a digital representation of the object, generating a digital representation of a build style lattice having a substantially uniform, conformal tetrahedron structure, overlaying the respective representations of the object and the build style, intersecting the overlaid representations to generate a digital representation of the object incorporating the build style; and fabricating the digital representation of the object incorporating the build style by solid free form fabrication.

Abstract: The invention provides a fluid power demonstration facility comprising means defining a fluid power source, directing means in fluid communication with the fluid power source and for selectively supplying fluid power from the fluid power source, pre-arranged rotary means, in fluid communication with the directing means, for demonstrating rotational motion produced in response to fluid power, and adapted to be selectively engageable by the directing means, and pre-arranged linear means, in fluid communication with the directing means, for demonstrating linear motion produced in response to fluid power, selectively engageable by the control means, and separate from the means for demonstrating rotational motion.