Massachusetts Institute of Technology

Other

Raytheon Company

Steven R Hall

Yet-Ming Chiang

Kyungyeol Song

Timothy E Chin

Urs Rhyner

Dimitrios Sapnaras

Fernando Tubilla

Yukinori Koyama

Herman R Person

Gregory L Malchow

Jesse M Simon

Joseph C Maiellano, Jr

Eric F Prechtl

Ross L Bisplinghoff

Joseph F Hesse

Joshua Chambers

William R Quinn

Janet Claire Hall

W Wallace White

Ronald L Spangler, Jr

Fernando Tubilla Kuri

Georg Baetz

E Timothy Chin

The present invention provides devices and structures and methods of use thereof in electrochemical actuation. This invention provides electrochemical actuators, which are based, inter-alia, on an electric field-driven intercalation or alloying of high-modulus inorganic compounds, which can produce large and reversible volume changes, providing high actuation energy density, high actuation authority and large free strain.

Electrochemical methods, devices, and structures

The present invention generally provides devices and methods involving electrochemical actuation. The devices may comprise at least one component capable of exhibiting a volumetric or dimensional change upon application of a voltage. In some cases, the volumetric or dimensional change may produce mechanical work. Some embodiments of the invention may provide devices capable of exhibiting high actuation rates and supporting high amounts of stress (e.g., in tensile and/or compressive loading). In some embodiments, the present invention may provide morphing structures that may be useful in applications such as airfoils.

The invention provides an acoustic actuator, including an acoustic stress wave generator and an actuation material operatively positioned relative to the acoustic stress wave generator for delivery of acoustic stress waves from the generator to the actuation material.

Acoustic pulse actuator

A New and improved stabilizer for use in conjunction with a wheelchair is disclosed. The device incorporates a multi part lever mechanism that is activated when no patient is seated on the seat area of the wheelchair, when the patient is preparing (or being assisted) to sit on the seat area and the patients weight is not fully pressing on the seat area, or the patient is getting up (or being assisted) from the seat area of the wheelchair and the patients weight pushing on the seat area is being reduced. The lever mechanism is deactivated when the seat area of the wheelchair is depressed by the patients weight. When the lever mechanism is activated a plurality of posts with tips that include friction means are pressed against the ground preventing the wheelchair from freely rolling in a backward direction.

Wheel chair rollback stop

An actuator having two frames, each frame including a distal end member, a proximal pivot end member or proximal end pivot point, and at least two elongated side members connected between the distal end member and the proximal pivot end member of that frame. A flexure is disposed between an end of the pivot end member of the first frame and an end of the pivot end member of the second frame. A first longitudinal span member is disposed between the distal end member of the second frame and the pivot end member of the first frame, and a second longitudinal span member is disposed between the distal end member of the first frame and the pivot end member of the second frame. At least one of the first and second longitudinal span members is an expansive element having a longitudinal axis along which dimensional strain can be induced in response to an applied stimulus. This expansive element extends in a state of compression between the corresponding distal and proximal pivot end members, with the longitudinal axis of the element in a plane parallel to side members of the first and second frames. The one or both of the longitudinal span members that are expansive elements can be, e.g., a magnetostrictive element, an electrostrictive element, or a piezoelectric element. The actuator provides many of the characteristics required to achieve optimal mass efficiency for a given set of actuator materials; and further provides advantages of high bandwidth, linearity, and large stroke performance advantages. As a result, the actuator can be adapted to many applications and can accommodate a range of engineering constraints.

High-efficiency, large stroke electromechanical actuator

Electrically deformable material such as piezoelectric material is used to deform a deflectable flap on an airfoil such as a helicopter blade. The electrically deformable material is controlled to deflect the flap in a manner to control vibrations transmitted from a helicopter blade to the helicopter air frame. In a preferred embodiment, the electrically deformable material and mechanical linkages are segmented along the length of the rotor blade. In this way, differential actuation of the deformable elements results in variable flap deflections along the length of the rotor.

Piezoelectric helicopter blade flap actuator

A washing machine having a mid-level pivot and traverse suspension system. The washing machine includes a tub assembly disposed over a support, with the assembly having a center of mass disposed at approximately the same axial position as the typical out-of-balance load. The pivoting force is a function of the distance between the center of mass of the tub assembly and the out-of-balance load. Thus, the pivoting forces are reduced, as well as the corresponding reaction forces transferred to the floor.

Washing machine having improved out-of-balance performance

The dot matrix plasma display of the present invention comprises a plurality of parallel cathode strips mounted on the upper surface of a dielectric substrate. A glass plate is sealingly engaged over the upper surface of the substrate in spaced relation thereto so as to form an envelope therebetween. The undersurface of the glass plate includes a plurality of anode strips which extend in a direction parallel to one another and perpendicular to the cathode strips located on the substrate below. A dielectric film is printed over the cathode strips and includes a plurality of apertures therein which correspond to the junctures between the anode strips and the cathode strips, these junctures forming a dot matrix. Ionizable gas is contained within the envelope and is adapted to glow adjacent the junctures of any simultaneously actuated anode and cathode strips. The method for driving the dot matrix plasma display includes actuating the cathode strips one at a time sequentially. Simultaneously with the actuation of each cathode strip, a pre-selected combination of anodes are also actuated so as to cause the gas to glow adjacent the junctures between the actuated anodes and cathode strips. The cathode strips are scanned at a frequency which to the human eye gives the appearance that they are constantly actuated.

Dot matrix plasma display and method for driving same

Growing community of inventors

Burlington, MA, United States of America

Steven R Hall