Massachusetts Institute of Technology

United States of America As Represented by the Administrator of Nasa

Kenneth C Cheung

Neil Adam Gershenfeld

Benjamin Jenett

Samuel Eli Calisch

Christine Gregg

Ara N Knaian

Charles Victor Fracchia

Nicholas Bryan Cramer

Daniel Walton Cellucci

Sarah Hovsepian

Sean Swei

Nadya Peek

David Watson

A shape-morphing ultralight structure using materials that dramatically increase the efficiency of load-bearing aerostructures that includes a programmable material system applied as a large-scale, ultralight, and conformable (shape-morphing) aeroelastic structure. The use of a modular, lattice-based, ultralight material results in stiffness and density typical of an elastomer. This, combined with a building block-based manufacturing and configuration strategy, enables the rapid realization of new adaptive structures and mechanisms. The heterogeneous design with programmable anisotropy allows for enhanced elastic and global shape deformation in response to external loading, making it useful for tuned fluid-structure interaction. The present invention demonstrates an example application experiment using two building block types for the primary structure of a 4.27 m wingspan aircraft with spatially programed elastic shape morphing to increase aerodynamic efficiency.

Elastic shape morphing of ultra-light structures by programmable assembly

A method for the design, manufacture, and assembly of modular lattice structures composed of cuboctahedron unit cells.

Cuboctahedron lattice materials

Method for discrete assembly of cuboctahedron lattice materials

A class of robots specifically adapted to climb periodic lattices. These 'relative robots' are designed for a specific lattice structure and use the regularity of the structure to simplify path planning, align with minimal feedback, and reduce the number of degrees of freedom (DOF) required to locomote. These robots can perform vital inspection and repair tasks within the structure that larger truss construction robots cannot perform without modifying the structure. A particular embodiment is a robot designed to traverse a cubooctahedral (CubOct) cellular solids lattice using only two motions: climbing and turning.

Mobile robot for locomotion through a 3-D periodic lattice environment

Flexural digital materials are discrete parts that can be assembled into a lattice structure to produce an actuatable structure capable of coordinated reversible spatially-distributed deformation. The structure comprises a set of discrete flexural digital material units assembled according to a lattice geometry, with a majority of the discrete units being connected, or adapted to be connected, to at least two other units according to the geometry. In response to certain types of loading of the structure, a coordinated reversible spatially-distributed deformation of at least part of the structure occurs. The deformation of the structure is due to the shape or material composition of the discrete units, the configuration of connections between the units, and/or the configuration of the lattice geometry. Exemplary types of such actuatable structures include airplane wing sections and robotic leg structures. An automated process may be employed for constructing an actuatable structure from flexural digital materials.

Flexural digital material construction and transduction

Digital flexural materials are discrete parts that can be assembled into a lattice structure to produce functionally useful assemblies. An automated process for constructing a structure from digital flexural materials includes assembling a set of discrete units into the structure by reversibly connecting a majority of the set of discrete units to each other, each of the units being reversibly connected or connectable to at least two other units in the set according to a lattice geometry, and then assembling the reversibly connected discrete units into the structure according to the lattice geometry, wherein the structure has the property that a reversible deformation of at least part of the structure occurs in response to loading of the structure. The units in the set of discrete units may be of at least two types or may together comprise a stretch-bend coupled material when assembled according to the lattice geometry.

Digital flexural materials

A robotic platform for traversing and manipulating a modular 3D lattice structure is described. The robot is designed specifically for its tasks within a structured environment, and is simplified in terms of its numbers of degrees of freedom (DOF). This allows for simpler controls and a reduction of mass and cost. Designing the robot relative to the environment in which it operates results in a specific type of robot called a 'relative robot'. Depending on the task and environment, there can be a number of relative robots. This invention describes a bipedal robot which can locomote across a periodic lattice structure made of building block parts. The robot is able to handle, manipulate, and transport these blocks when there is more than one robot. Based on a general inchworm design, the robot has added functionality while retaining minimal complexity, and can perform numerous maneuvers for increased speed, reach, and placement.

Bipedal isotropic lattice locomoting explorer: robotic platform for locomotion and manipulation of discrete lattice structures and lightweight space structures

A digital material skin is made of a set of discrete units with a finite set of parts and joints. The discrete units are assembled into a layer according to a regular geometry, with each of the discrete units being reversibly connected to at least one other unit in the set. The reversibly connected set of units forms an exterior structure surface that is larger than the individual discrete units. Digital material skins may be used to construct any shape or interior volume, whether regular or amorphous. The skin surface may be enclosed or open. The skin may rely on an interior digital material structure for support or may be self-supported. The skin may be part of a larger assembly or apparatus, enclosing an interior volume or structure.

Methods and apparatus for digital material skins

Digital flexural materials are kits of discrete parts that can be assembled into a lattice structure to produce functionally useful assemblies. Digital flexural materials enable design of materials with many small and inexpensive flexures that combine in a lattice geometry that permits deformation without compromising the strength of the assembly. The number of types of parts in a kit is small compared to the total number of parts. A product constructed from digital flexural materials comprises a set of discrete units that are assembled into the structure according to a lattice geometry, with a majority of the units being reversibly connected to at least two other units in the set according to the lattice geometry, and wherein, in response to loading of the structure, a reversible deformation of at least part of the structure occurs. An automated process may be employed for constructing a product from digital flexural materials.

In exemplary implementations of this invention, hierarchical, nanometer-precise assembly is performed: A first structural unit is attached to a solid substrate in a first fluidic flow. A second structural unit is attached to the first structural unit in a second fluidic flow, a third structural unit is attached to the second structural unit in a third fluidic flow, and so on, until a target structure comprising the structural units is assembled. The first, second, third and so on fluidic flows are separate and occur in order in a temporal sequence. During the temporal sequence, a specific permutation of nucleobases is used repeatedly, in separate fluidic flows which occur at different times, to form multiple attachments between structural units in an assembly. The assembled target structure is removed from the solid substrate. Attachments between the structural units may be formed by nucleobase pairing.

Methods of serial assembly of DNA bricks into larger structures

In exemplary implementations of this invention, a digital material comprising many discrete units is used to fabricate a sparse structure. The units are reversibly joined by elastic connections. Each unit comprises fiber-reinforced composite material. Each unit is small compared to the sparse structure as a whole. Likewise, in a sparse structure made from this digital material, the number of types of units is small compared to the total number of units. The digital material is anisotropic. This anisotropy may be due to different fiber orientations within each unit. Furthermore, different units in a single sparse structure may be oriented in different directions and in different, non-parallel planes. In some cases, the digital material is reinforced with carbon fibers, and connections between units are stronger than the units themselves. The small discrete units may be assembled into a strong, lightweight sparse structure, such as an airframe.

Methods and apparatus for digital composites

Cellular automotion digital material is useable for rapid prototyping and fabrication of continuous string conformations and two- or three-dimensional shapes through actuation of a string, surface, or volume composed of identical discrete units. Each unit is an actuated joint having a single degree of freedom. The actuated joint includes a two-part actuator having an inner active portion and an outer passive portion that are controllably rotatable relative to each other, the outer portion being configured to fit within the housing of an adjacent cellular automotion unit, and a linkage element that includes a main strut and a housing and is connected to the actuator by a pin connector. The housing is configured to house the actuator of an adjacent cellular automation unit, and the opening in the strut is rotated about the axis of symmetry of the cellular automotion unit relative to the opening in the housing so that the alignment of the cellular automotion unit will be rotated with respect to the alignment of any adjacent unit. The cellular automotion unit may include an on-board processor for controlling actuation of the cellular automotion unit.

Cellular automotion digital material

In exemplary implementations of this invention, a network of nodes controls and senses the cure of a thermosetting plastic in a component that is made of fiber composite material. The network comprises multiple nodes, which are separated spatially from each other. Each of the nodes, respectively, comprises a heat transfer device for actively transferring thermal energy, a temperature sensor for taking local temperature measurements, and a processor. In each of the nodes, respectively: (a) the processor locally performs closed loop control over the temperature of the heat transfer device, and (b) the closed loop control is based at least in part on the local temperature measurements and on estimated or measured input current to the heat transfer device.

Growing community of inventors

Boston, MA, United States of America

Kenneth C Cheung