Actuator
The control signal is relatively low in energy and may be voltage, electric current, pneumatic, or hydraulic fluid pressure, or even human power[clarification needed].
A hydraulic actuator typically uses the pressure of a liquid (usually oil) to cause a piston to slide inside a hollow cylindrical tube linear, rotatory or oscillatory motion.
In a double acting actuator, the return stroke is driven by fluid pressure applied to the opposite side of the piston.
[8][9] Compared to hydraulic actuators, pneumatic ones are less complicated because they do not need pipes for the return and recycling of the working fluid.
On the other hand, they still need external infrastructure such as compressors, reservoirs, filters, and air treatment subsystems, which often makes them less convenient that electrical and electromechanical actuators.
Applications for the rotary actuators are just about endless but, will more than likely be found dealing with mostly hydraulic pressured devices and industries.
Anything you see that deals with motion control systems to perform a task in technology is a good chance to be a rotary actuator.
Because it generally has lower friction losses than the alternatives, a linear electric actuator can last over a hundred million cycles.
Linear motor technology is the best solution in the context of a low load (up to 30Kgs) because it provides the highest level of speed, control and accuracy.
The growing interest for this technology, can be explained by the following characteristics: The main disadvantages of linear motors are: An actuator may be driven by heat through the expansion that most solid material exhibit when the temperature increases.
They typically contain parts made of ferromagnetic materials that are strongly attracted to each other when they are magnetized by the external field.
A soft actuator is made of a flexible material that changes its shape in response to stimuli including mechanical, thermal, magnetic, and electrical.
The soft actuators apply to mainly safety and healthcare for humans which is why they are able to adapt to environments by disassembling their parts.
[13] This is why the driven energy behind soft actuators deal with flexible materials like certain polymers and liquids that are harmless The majority of the existing soft actuators are fabricated using multistep low yield processes such as micro-moulding,[14] solid freeform fabrication,[15] and mask lithography.
They also enable incorporation of all actuator components into a single structure eliminating the need to use external joints, adhesives, and fasteners.
Shape memory polymer (SMP) actuators are the most similar to our muscles, providing a response to a range of stimuli such as light, electrical, magnetic, heat, pH, and moisture changes.
The advent of 3D printers has made a new pathway for fabricating low-cost and fast response SMP actuators.
The process of receiving external stimuli like heat, moisture, electrical input, light or magnetic field by SMP is referred to as shape memory effect (SME).
SMP exhibits some rewarding features such a low density, high strain recovery, biocompatibility, and biodegradability.
The LAP actuators can be controlled remotely with instant response and, without any physical contact, only with the variation of light frequency or intensity.
