This document discusses different types of actuators used in IoT devices. It defines an actuator as a machine component that moves or controls a mechanism. Actuators help achieve physical movement by converting electrical, air, or hydraulic energy into mechanical force. The document describes several common types of actuators, including linear and rotary actuators, as well as actuators powered by hydraulics, pneumatics, electricity, thermal changes, magnetism, and supercoiled polymers.

1. ACTUATORS IN IOT

2. INTRODUCTION:
• An IoT device is made up of a Physical object (“thing”) +
Controller (“brain”) + Sensors + Actuators + Networks
(Internet).
• An actuator is a machine component or system that moves or
controls the mechanism of the system.
• Sensors in the device sense the environment, then control
signals are generated for the actuators according to the
actions needed to perform.
• Actuators help achieve physical movements in a device by
converting electrical, air or hydraulic energy into mechanical
force.

3. BLOCK DIAGRAM

5. 1. Motion
The two primary motions that actuators can produce are linear and rotary.
a. Linear actuators
Ø Tools that generate movement along a straight line are known as linear actuators.
They typically appear in hydraulic or pneumatic equipment and might be
mechanical or electrical. A linear actuator is usually present in any device that
needs to move in a straight line.
Ø A nut, cover, and sliding tube make up a primary linear actuator. While the nut
and cover provide the interlocking motion that ensures the actuator moves in a
straight line, the sliding tube creates room for action.
Ø This simple device is the basis for straight movement, while other sophisticated
linear actuators will include additional elements.

6. b. Rotary actuators
Ø Rotary actuators generate a circular motion as opposed to linear actuators.
Since most machines use these rotating components to complete a turning
movement, they are referred to as "rotary" machines.
Ø If a machine needs to move up, down, forward, or backward, they are
frequently employed in tandem with a linear actuator motor.
Ø Hydraulic or pneumatic systems power several rotational actuators in addition
to the majority powered by electricity.
Ø Electric fans, windscreen wipers, and industrial equipment moving products
from one location to another use rotational actuators.

7. 2. Source of energy
a. Hydraulic actuators
Ø With the help of a cylinder or fluid motor, hydraulic actuators can provide
mechanical motion, producing linear, rotatory, or oscillatory motion.
Ø A hydraulic actuator can make a significant amount of force since liquids are
essentially challenging to compress.
Ø A force is applied to the bottom of the piston, which is also inside the hydraulic
cylinder of the actuator, when the fluid enters the lower chamber of the cylinder.
Ø The sliding piston is moved upward, and the valve is opened by the pressure,
which carries the piston in the opposite direction of the force produced by the
upper chamber's spring.

8. b. Pneumatic actuators
Ø Compressed air energy is transformed into mechanical motion by pneumatic
actuators. In this instance, compressed air or gas is introduced into a chamber to
increase pressure.
Ø A straight or circular mechanical motion results when this pressure rises above
the necessary pressure levels compared to the atmospheric pressure outside the
chamber. This happens when the piston or gear is moved kinetically in a
controlled manner.
Ø Air cylinders, pneumatic cylinders, and air actuators are some examples. It is
dependable, has a long working life, and requires little maintenance.
Ø The motion starts and stops very quickly, making the actuator reliable.
Ø Air requires upkeep and is subject to pollution.The pressure loss could reduce its
effectiveness.

9. c. Electric actuators
i. Electromechanical actuators:
Ø When an electric motor replaces the control knob or handles on a mechanical
actuator, the device is called an electromechanical actuator.
Ø The motor's rotating motion causes linear displacement.
ii. Electrohydraulic actuators:
Ø Electrohydraulic actuators are self-contained actuators that only use electrical
power, unlike hydraulic systems.
Ø In essence, they are utilized to operate tools like multi-turn valves or electric-
powered construction and excavation machinery.
Ø The electrical actuators were initially created for the aerospace sector. However,
today they are used in many other industries - wherever hydraulic power is
employed.

10. d. Thermal actuators:
Ø A non-electric motor known as a thermal actuator produces linear motion in
reaction to temperature variations.
Ø A piston and a thermally sensitive substance make up its essential parts. The
thermally sensitive materials start to expand in response to a rise in temperature,
which forces the piston out of the actuator.
Ø Similarly, when the temperature drops, the thermally sensitive components within
the contract cause the piston to withdraw.
Ø Besides operating latches, switches, and open or close valves, these actuators can
be utilized for other functions.
Ø They have a wide range of uses, mainly in the solar, automotive, agricultural,
and aerospace sectors.

11. e. Magnetic actuators:
Ø Actuators that use magnetic effects to move a component are known as magnetic
actuators.
Ø The movement in magnetic actuators is brought around by the magnetic field. It is
known as the Joule effect and sometimes occurs simply with a coil's placement in a
static magnetic field. The Laplace-Lorentz force causes constant motion of the
actuator.
Ø They often fall into the following groups:
Ø electromagnetic actuator, moving coil actuator, magnet actuator, and moving iron
actuator. They are lightweight yet capable of making powerful movements.

12. f. Mechanical actuators
Ø Mechanical actuators move by transforming one type of motion, such as rotary
motion, into another, such as linear motion.
Ø .A chain block hoisting weight is another illustration in which a load is raised
using the mechanical motion of the chain.
Ø Mechanical actuators depend on the interactions of the structural elements that
make them up, such as gears and rails or pulleys and chains.
Ø Among the benefits are high dependability, ease of use, more straightforward
maintenance, and improved positioning precision. Actuators can be classified as
hydraulic, pneumatic, or electronic.

13. g. Supercoiled polymer actuators
Ø Actuators made of supercoiled polymer are a relatively recent addition to the
various forms of actuators.
Ø Because they can mimic the motion of human muscle using a coil that contracts
and expands when heated or cooled, they are employed in robotics and prosthetic
limbs.