Abstract:
A deployment module according to the present application enables both compact stowage of a sensor array and expansion of the sensor array into a three-dimensional volumetric array shape that enables improved directionality of the sensors during operation. The deployment module includes a support shell that is configured to retain a cable of the sensor array separately from sensors of the sensor array and an expandable deployment body formed of a superelastic shape memory alloy that uses superelasticity and stored energy for deployment of the sensor array. During deployment, the deployment body is removed from the support shell and the sensors are subsequently pulled out of the support shell. The deployment body then expands and holds the cable to retain the three-dimensional volumetric shape of the deployed array.
Abstract:
A solid rocket motor uses at least one thermally conductive wire or at least one pair of electrically conductive wires to increase a burn surface area of a propellant grain and thus a thrust of the rocket motor. The rocket motor includes a pulse chamber containing a burnable propellant grain, a propellant inhibited center bore bonded to surfaces of the burnable propellant grain, and at least one conductive wire coupled to the burnable propellant grain and arranged in variable regions along the propellant inhibited center bore. The conductive wire is configured for passive or active activation to ignite the propellant inhibited center bore that subsequently burns in the variable regions. The thermally conductive wire is formed of a refractory metal or refractory alloy material that enables the entire length of the wire to be heated simultaneously or nearly simultaneously when the wire is passively activated.
Abstract:
A device is provided. The device includes at least one SMM component fabricated from an SMM. The SMM component is configured to change shape in response to receiving a stimulus. The SMM component is also configured to deploy from a device body of the device allowing the device to change shape in an advantageous way. A method implemented by a device is also provided. The method includes changing a shape of an SMM component of the device in response to receiving a stimulus. The SMM component is fabricated from an SMM. The method also includes deploying the SMM component from a device body of the device allowing the device to change shape in an advantageous way.
Abstract:
A satellite has thrusters that are integral parts of its frame. The frame defines cavities therein where thrusters are located. The thrusters may include an electrically-operated propellant and electrodes to activate combustion in the electrically-operated propellant. The frame may be additively manufactured, and the propellant and/or the electrodes may also be additively manufactured, with the frame and the propellant and/or the electrodes also being manufactured in a single process. In addition the thrusters may have nozzle portions through which combustion gases exit the thrusters. The thrusters may be located at corners and/or along edges of the frame, and may be used to accomplish any of a variety of maneuvers for the satellite. The satellite may be a small satellite, such as a CubeSat satellite, for instance having a volume of about 1 liter, and a mass of no more than about 1.33 kg.
Abstract:
A shape memory circuit breaker includes a shape memory substrate having first and second opposed substrate ends. The shape memory substrate is configured to transition from a strained conductive configuration to a fractured non-conductive configuration. An isolation housing is coupled with the shape memory substrate. The isolation housing includes first and second anchors coupled near the first and second substrate ends. A brace extends between the first and second anchors, and the brace statically positions the first and second anchors and the respective first and second substrate ends. The shape memory substrate is configured to transition from the strained conductive configuration to the fractured non-conductive configuration at or above a specified temperature range corresponding to a specified overload current range or voltage range, and the first substrate end fractures from the second substrate end at or above the specified temperature range resulting in an open circuit.
Abstract:
A method of making a reconfigurable three-dimensional shape includes the following steps: (i) moving multiple print heads in three dimensions relative to a printing surface, where the print heads include a conductor print head and a polymer print head; (ii) depositing a conductive material from the conductor print head; and (iii) depositing a shape-memory polymer from the polymer print head. The depositing steps form a volumetric shape of a shape-memory polymer, capable of changing shape, with a conductive material capable of acting as a heating element integrally formed in the volumetric shape. The method can further include the steps of heating the shape-memory polymer above a transition temperature, changing the shape of the volumetric shape following the heating step, and then allowing the shape-memory polymer to cool below the transition temperature to fix the new volumetric shape.
Abstract:
A control system for a missile includes a plurality of control surfaces that can be arrayed across a surface of the missile body, and a controller connected to the control surfaces to selectively move the control surfaces between an aerodynamic stowed position where the control surfaces conform to the surface of the body, and a deployed control position removed from the aerodynamic stowed position where the control surfaces extend from the surface of the body to interact with airflow over the body. The control surfaces are made of a material that includes a shape-memory alloy. Heating the control surfaces causes the shape-memory alloy to move the control surfaces from the aerodynamic stowed position to the deployed control position. By selectively extending and retracting the control surfaces, the control system provides the ability to control the missile's direction of travel or to reduce roll about a longitudinal axis of the body.
Abstract:
A robotic finger includes a shape-memory alloy and a shape-memory polymer connected to and adjacent to the shape-memory alloy. Heating the shape-memory polymer causes it to soften, heating the shape-memory alloy causes the alloy to bend in the direction of the shape-memory polymer to press the shape-memory polymer against an object to be grasped, and cooling the shape-memory polymer causes it to stiffen and to retain its shape. An opposing member is positioned to cooperate with the finger to grasp an object positioned between the finger and the opposing member. A selectively controllable heat source is capable of applying heat to the finger.
Abstract:
A solid rocket motor uses at least one thermally conductive wire or at least one pair of electrically conductive wires to increase a burn surface area of a propellant grain and thus a thrust of the rocket motor. The rocket motor includes a pulse chamber containing a burnable propellant grain, a propellant inhibited center bore bonded to surfaces of the burnable propellant grain, and at least one conductive wire coupled to the burnable propellant grain and arranged in variable regions along the propellant inhibited center bore. The conductive wire is configured for passive or active activation to ignite the propellant inhibited center bore that subsequently burns in the variable regions. The thermally conductive wire is formed of a refractory metal or refractory alloy material that enables the entire length of the wire to be heated simultaneously or nearly simultaneously when the wire is passively activated.
Abstract:
A deployment body for a sensor array includes at least one superelastic spring formed of a shape memory alloy (SMA) material that enables activation of the deployment body. The SMA spring is configured to expand from a stowed position in which the SMA spring is wound around a central hub of the deployment body to a deployed position in which the SMA spring is extended in a radially outward direction relative to the central hub. A stiffness of the SMA spring enables the SMA spring to hold cables of the sensor array and maintain a deployed shape of the sensor array, which may be a volumetric array. Using the SMA material is advantageous in that the material is tuned to maintain superelasticity based on at least one of an intended operating temperature and a desired expansion ratio of stowed to deployed diameter of the deployment body.