Publications
Categories
New range of light driven actuation devices
12 October 2023
The recent progresses made in the manufacturing of new plasmonic photomobile films are offering innovative solutions for light induced motion actuators and devices. Indeed, such films can be assimilated as transducers thanks to their ability to convert light into displacement with strokes up to several millimeters. By adjusting the incident light parameters (wavelength, exposure time…) the photomobile films actuation can be controlled to answer many applications requesting high displacements and low forces. In these regards, the behaviour of the photomobile films were characterized prior to their integration in more complex devices. Then, several proof-of-concepts of these devices were manufactured to try to bring new functionalities to the market such as light driven optical switch, optical micro-valve, and deflector:
– The optical switch features interesting properties in term of electrical insulation by eliminating the dark currents responsible for noise in image sensors. It also exploits the large stroke of the photomobile films to achieve the standard electrical insulation distance versus emitter voltage.
– Light driven micro-valves/micro-pumps are suitable for delivering a small quantity of fluids with high precision for example in medical devices. Using this technology, a fluid circuit can be opened and closed when light is switched from on to off (or inversely) without embedded electric power.
– Optical deflectors are used widely in optical pointing applications where fast responses and/or high precisions are critical. An appropriate understanding of the photomobile films behaviour enables to control the direction of the beam deflection within large angular ranges.
Viscoelastic properties of the ferret brain measured in vivo at multiple frequencies by magnetic resonance elastography
19 June 2023
Characterization of the dynamic mechanical behavior of brain tissue is essential for understanding and simulating the mechanisms of traumatic brain injury (TBI). Changes in mechanical properties may also reflect changes in the brain due to aging or disease. In this study, we used magnetic resonance elastography (MRE) to measure the viscoelastic properties of ferret brain tissue in vivo.
The design and qualification of the piezo actuated
19 June 2023
As part of the Lisa Technology Package (LTP) on board the LISA-PATHFINDER spacecraft, the LISAPATHFINDER interferometer is of the heterodyne Mach-Zehnder type. It requires as input two light beams derived from the same source but with a small frequency difference (a few kHz). These two optical beams are produced in the Laser Assembly (LA) via the “Laser Modulation Unit” (LMU). The LMU includes an optical bench, two Acousto-Optic Modulators and two Optical Delay Lines [1].
Tool adaptor for active vibration control in turning operations
19 June 2023
A tool adaptor with built-in active vibration damping device to dynamically stabilize the turning process is presented in this paper. It can be used in standard CNC-lathes and allows the usage of off-the-shelf tool heads. The vibration compensation system is based on a multilayer piezoactuator that is in collocation with a piezoelectric force sensor. An analogue controller based on the integral force feedback method is used for active damping.
Very Compact Integration of an Ultra-Low Vibration Platform for Space Cryocoolers Using Miniature High Frequency Actuators
19 June 2023
Air Liquide advanced Technologies in collaboration with Cedrat Technologies and SMAC has performed a study of a compact vibration control platform for mechanical cryocoolers. This solution has been proposed as an alternative approach to cryocooler integration with respect to suspended systems that must be mechanically locked during the launch phase. This system allows significant reduction of the platform’s physical size and mass.
Vibration energy harvesting in aircraft using piezoelectric actuators
19 June 2023
In the aicrft vehicle, a part of the produced energy is transformed into mechanical vibration energy losses. This rue is more than ever true when the need for electrucal energy is a crucial problem. So, systems which are able to transform the mechanical energy in a scavenged electrical energy are very interesting.
