A haptic actuator device includes a surface with a mechanical property responsive to localized temperature changes. The surface can include a layer or sheet comprising a shape-memory material. The haptic actuator device can further include an actuator configured to selectively deform a plurality of regions in the sheet; and a temperature controller adapted to control the temperatures of the plurality of regions. A method of localized actuation includes selectively controlling the temperatures of the plurality of regions to be above a shape-memory transition temperature of the shape-memory material; selectively deforming at least one of the regions; while maintaining the deformation of the at least one region, lowering the temperature of the at least one region to below the shape-memory transition temperature; subsequently withdrawing the applied stress; and thereafter heating the at least one region to above the shape-memory transition temperature, causing the region to return to its pre-deformation shape.

A device may comprise a substrate formed of a first semiconductor material and a trench formed in the substrate. A second semiconductor material may be formed in the trench. The second semiconductor material may have first and second portions that are isolated with respect to one another and that are isolated with respect to the first semiconductor material.

An active cooling system includes at least one cooling element that has a vent therein. The active cooling element is in communication with a fluid. The cooling element(s) are actuated to vibrate to drive the fluid toward a heat-generating structure and to alternately open and close at least one virtual valve corresponding to the vent. The virtual valve is open for a low flow resistance and closed for a high flow resistance. The vent remains physically open when the virtual valve is closed.

A microelectromechanical device comprising a mechanical structure extending along a longitudinal direction, linked to a planar substrate by an anchorage situated at one of its ends and able to flex in a plane parallel to the substrate, the mechanical structure comprises a joining portion, which links it to each anchorage and includes a resistive region exhibiting a first and second zone for injecting an electric current to form a resistive transducer, the resistive region extending in the longitudinal direction from an anchorage and arranged so a flexion of the mechanical structure in the plane parallel to the substrate induces a non-zero average strain in the resistive region and vice versa; wherein: the first injection zone is carried by the anchorage; and the second injection zone is carried by a conducting element not fixed to the substrate and extending in a direction, termed lateral, substantially perpendicular to the longitudinal direction.

A microelectromechanical structure with electrothermal actuation including a fixed part, a moveable part, a first electrothermal actuating beam enabling an electric current to flow from the fixed part to the moveable part and a second electrothermal actuating beam enabling an electric current to flow from the fixed part to the moveable part, the beams being mechanically connected to the moveable part enabling a displacement of the moveable part by electrothermal actuation, an electrically conductive connecting element connecting the moveable part to the fixed part, a first connector for connecting the first actuating beam to a first polarisation source and a second connector for connecting the second actuating beam to a second polarisation source, such that the first and the second can be polarised differently and separately.

A microelectromechanical device comprising a mechanical structure extending along a longitudinal direction, linked to a planar substrate by an anchorage situated at one of its ends and able to flex in a plane parallel to the substrate, the mechanical structure comprises a joining portion, which links it to each anchorage and includes a resistive region exhibiting a first and second zone for injecting an electric current to form a resistive transducer, the resistive region extending in the longitudinal direction from an anchorage and arranged so a flexion of the mechanical structure in the plane parallel to the substrate induces a non-zero average strain in the resistive region and vice versa; wherein: the first injection zone is carried by the anchorage; and the second injection zone is carried by a conducting element not fixed to the substrate and extending in a direction, termed lateral, substantially perpendicular to the longitudinal direction.

An ultra low power thermally-actuated oscillator and driving circuit thereof are provided. The ultra low power thermally-actuated oscillator includes proof masses, thermally-actuated element and a plurality of driving elements. The proof masses is symmetrically disposed and suspended from a substrate by spring structure. The thermally-actuated element is a line structure to effectively reduce the motional impedance and direct current power. Wherein, the thermally-actuated element is connected to the proof masses or the spring structure. The plurality of driving elements are respectively disposed on both sides of the thermally-actuated element to provide a driving current. When the driving current flows through the thermally-actuated element, the thermally-actuated element will be deformed and thus the proof masses will be driven to produce a harmonic oscillation.

A device for generating a second temperature variation T.sub.2 from a first use temperature variation T.sub.1, includes an elastocaloric material layer, having an internal temperature which is able to vary by T.sub.2 in response to a given mechanical stress variation applied to the elastocaloric material layer. The variation being induced by the first use temperature variation T.sub.1 There is a suspended element in mechanical contact with the elastocaloric material layer so as to apply to this layer a mechanical stress that varies in response to the use temperature variation T.sub.1. The suspended element is arranged so as to make the mechanical stress applied to the elastocaloric material layer vary by in response to the temperature variation T.sub.1, to generate the second temperature variation T.sub.2.

An active cooling system is described. The active cooling system includes at least one cooling element that has a vent therein and is in communication with a fluid. The cooling element(s) are actuated to vibrate to drive the fluid toward a heat-generating structure and to alternately open and close at least one virtual valve corresponding to the vent. The virtual valve is open for a low flow resistance and closed for a high flow resistance. The vent remains physically open for the virtual valve being closed.

A micro-electromechanical system (MEMS) device includes a silicon substrate; and a Tantalum (Ta) layer comprising a first portion and a second portion, a first portion being suspended over the silicon substrate and configured to move relative to the silicon substrate, and the second portion of the structure being coupled to the silicon substrate and fixed in place relative to the silicon substrate.