Linear actuators
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Inertial & Inchworm piezoelectric motors: Design and Motorization selection key aspects
14 June 2024
Piezoelectric motors have gained increasing prominence in various applications due to their unique capabilities and advantages. These motors are adapted for applications which require non-magnetic and radiation compatibility, high force/volume ratio, good unpowered stall force and low power consumption. Cedrat Technologies (CTEC) have developed inertial and inchworm motorization for a wide range of application such as Space, Defense and Nuclear. Each motorization solution has its own advantages and disadvantages which are discussed in this paper. Key aspect for the design and key element for the motorization selection are presented below.
Light-controlled mechanisms based on photomobile polymers for seamless integration in demanding environments
14 June 2024
Photomobile polymers (PMP) are active materials that convert light into mechanical movement. They can be used in energy harvesters, light-controlled actuators, or mechanisms. Because they are controlled by light and work without electricity, they offer unique opportunities for designing devices that can be integrated seamlessly and that require virtually no maintenance. This finds interest in fields like nuclear energy, medical implants, biology, space, or Internet of Things (IoT). Cedrat Technologies have designed, built, and tested 3 proof of concept prototypes: a mechanical switch, a mechanical valve, and an optical deflector. The present paper will present these 3 concepts and the tests results in detail.
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.
Optimized high-efficiency MICA actuators for space compressors
14 June 2024
Moving Iron Controllable Actuators MICA™ are magnetic linear actuators from CEDRAT TECHNOLOGIES (CTEC) that find interests in applications requiring high-force density and low heating. Because of these attractive performances, some space applications such as ZBO Gas compressors and Pulse Tube Cryocooler are considering their use in operational missions. However, this last application requires the demonstration of additional features, notably a high efficiency, a long lifetime and a good force homogeneity to minimize the generation of exported micro-vibrations. To fulfil these additional features, CTEC has developed an optimised MICA following the specifications of the Pulse Tube Cryocooler (PTC) of AIR LIQUIDE. The paper will present the performance progresses obtained on this customized MICA, from modelling prediction to lab tests of Engineering Models.
Manufacture and properties of first industrial actuators APA® using carbon epoxy SHELLS
12 February 2012
Future aeronautics will more often use electrical actuators in order to replace hydraulic actuators. Existing Amplified Piezo Actuators APA® with steel shell, delivering among the highest mass energy densities, are good candidates. Lighter carbon shells are developed to further increase their efficiency. For helicopters rotor blade application this evolution is almost unavoidable but is also very interesting for other domains. High modulus and high tensile strength carbon fibres shells have been produced by conventional filament winding, tested and compared.
Mechanical structure with high force amplification ratio for low frequency piezoelectric harvester application
19 June 2023
A mechanical structure based on serial stacking of level arm has been designed in order to amplify the ingoing force of the the harvester system. The outgoing force is applied upon the smart material. The deformation of the mechanical structure is based on flexural pivots using four truncated circular collars. The last amplification is based on the APA® (Amplified Piezoelectric Actuator) shell and already patented solution by Cedrat Technologies. The force amplification structure has been designed upon the request of a small volume allocated (0.3 cm3) and low frequency resonance (20 Hz) harvester
