Linear actuators
Categories
Bistable micro actuator for energy saving
19 June 2023
The article describes a linear magnetic flip-flop micro actuator, designed with FLUX software, assembled and characterised for a specific application requiring low losses at function states. The micro size allows reducing the energy required for actuation. Permanent magnets ensure bistability and suppress losses at functional states. Although the actuator is less than 1 g, the blocking force is about 0.1N and the stroke is 0.6mm. Firstly, the paper describes the main functionality of the actuator. Then are presented measured characteristics and results are compared with FLUX software computation. Finally perspectives of further miniaturisation are discussed.
BRUCE – Electromagnetic Actuated Pin Puller
12 January 2012
Pin pullers are used to hold, lock or secure deployable or moving parts on spacecrafts during their launching. These ‘one shot’ actuators used to be based on explosive charges. Pin pullers important characteristics are their retraction force that needs to be sufficient to pull the pin out of the locking mechanism, their maximum radial force, which limits the size of the secured system, and their dimensions and weight. The possibility of resetting the mechanism is also an appreciated advantage. Upon request of CNES, the French National Space Agency, CEDRAT TECHNOLOGIES has designed a resettable electromagnetic actuated pin puller, called BRUCE
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.
Electro-fluidic components based on smart materials for aircraft electro-hydraulic
19 June 2023
In the context of a more electrical aircraft, in order to explore the feasibility of non usual solutions, electro-fluidic components based on smart materials and new Electro-Hydraulic-Actuators (EHA) concepts, based on active valves and magnetostrictive vibrating pump, have been studied. Active valves based on different magnetostrictive and piezoelectric actuators have been designed, realised, tested and compared. The magnetostrictive version uses a new Amplified Magnetostrictive Actuator (AMA) based on a stack of Giant Magnetostrictive Materials (GMM) and placed inside an elliptical amplification ring.
Vibration isolation of an extended object
19 June 2023
An increasing number of applications required a very high level of precesion: semiconductor manufacturing, atomic force microscopy, scanning probe microscopy, machine tool, etc. Such high precision can only be reached in very stable environments. the standard procedure is to mount the sensitive equipment on a heavy isolating stage, sometimes referred to as optical table, which can be either passive or active.
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.
