If it is required to take controlled small steps (without the use of position encoders) a stepper motor is an interesting option for micro actuators. The rotor contains permanent magnets and the stator contains electromagnets. The rotor has many poles and aligns itself with one of the poles of the stator. Each time a different stator pole is excitated the motor rotates a little bit (= one step). Stepper motors are very reliable and have a long lifetime but they cannot deliver high speeds or very stable speeds. A stepper motor is really a positioning motor and has been one of the only options for precise positioning in a time where servo motors were not developed yet.
The lead screw concept is one of the simplest yet sturdiest designs possible for micro actuators. Imagine a nut on a bolt. Now rotate the nut while you hold the nut at the position and the bolt will slowly move up or down. You will find these actuators in low budget applications or applications that require large forces, like drill presses. The motor inside can be a brushed or brushless DC motor or a stepper motor. A lead screw actuator is cheap but is slow and has a lot of friction. Because of the friction a larger motor is needed to drive the actuator. Thanks to the high friction, many lead screw actuators are self locking when there is no power. Micro actuators with lead screws are bulky because a strong motor is needed to overcome the friction. Most compact linear actuators are ball-screw designs instead of lead-screw.
A ball screw actuator is the improved version of a lead screw actuator. The contact between the shaft and the nut is handled by recirculating balls instead of a sliding contact. Ball screw actuators can be combined with different kinds of motors. Micro actuators with a ball screw are affordable but can be bulky because of the motor sitting next to the shaft. Most models cannot achieve speeds higher than 50 mm/s. Imperfections in the screw lead to play and backlash. In most micro linear actuators, this backlash is in the order of 0,1 mm. For applications that really require a small form factor, a ball screw actuator often is too bulky.
A linear motor is a different motor principle than the motors discussed so far in this document. All motors so far create a rotation of some kind which is translated into a linear motion by a transmission component, like a rack or a threaded shaft. A linear motor is an electromagnetic motor that creates a linear motion by default without any transmission components. The design resembles a brushless DC motor but the (permanent) magnets are not put in a circle but in two straight lines. They form a linear stator. The moving part of the motor contains windings and needs multiple sine waves to be driven, just like a brushless DC motor. By the nature of the design a linear motor is very suitable to be used as a linear actuator. But there is a challenge: Linear motors are bulky and heavy because of the magnets and are also more expensive than ball screw actuators. They can deliver a lot of force and achieve high speeds. When powered there is always some jitter (small vibrations) to stay in position. When unpowered they are not self locking.
A voice coil actuator is basically the same design as a linear motor, but with one winding instead of a series of multiple windings. The outer shell is a (permanent) magnet and the inner part slides in and out of the shell because of the magnetic field. By changing the current in these windings, the speed and force of the voice coil actuator can be altered. Voice coils are precise and durable, but unfortunately they have two major downsides: They are not suitable for long travel ranges, because of the use of only one winding, and they are expensive. Most voice coil actuators have strokes of less than 10 mm.
The solenoid actuator is another very basic linear actuator principle. An electromagnetic coil pulls a metal core inside the shell. A solenoid is super cheap but is an all-or-nothing actuator because the more the metal core slides inside the electromagnet the harder it is pulled upon. So it accelerates until it hits the end stop. Typically the actuator is moved back by a mechanical spring. A solenoid can only be fully opened or fully closed without any speed control, making them unsuited for many applications where other miniature actuators are used.
If you’re not familiar with the principle of piezo motors, make sure to read our other pages on the fundamentals of piezo motors. The first type is a stick-slip piezo motor. It moves back and forth at a high frequency against an object that needs to be moved or rotates. It sticks in one direction but slips in the other, resulting in a very small net displacement but also in a short lifetime of the motor. If this kind of motor is used on a lead-screw-like design, you end up with a piezo actuator, like the one in the picture below. They are extremely precise but move slowly (< 2 mm/s). Typically these kinds of actuators don’t have travel ranges longer than 50 mm. They are very expensive and mostly used in scientific applications.
On our page on the basic principles of piezo motors you will also find the walking piezo (or stepping piezo). In contrast with the stick-slip principle described above, the walking piezo concept contains multiple piezo elements that extend one after the other, allowing for a retreat action without friction. The result is a better lifetime and higher maximum speed (< 30 mm/s). The complex ballet of multiple piezo elements drives up the price. As in most models the driving rod needs to be made out of ceramic material, the travel length is limited. A walking micro piezo actuator travel range typically is limited to 20 mm.
The piezo actuators described above are precise but slow. For short travel ranges this can be acceptable but if you need to travel 300 mm you do not want to wait two minutes for the actuator to extend. In that case an ultrasonic piezo actuator could be a solution. We have a page describing the technology of ultrasonic piezo motors in detail and one covering our patented ultrasonic piezo motor itself. In short, in this design, the piezo element vibrates in resonance, which increases the extensions and contractions of the piezo element.
The result is a travel speed of mm/s and noiseless motion. Stick-slip piezo systems are characterized by a typical buzzing noise as they vibrate within the audible spectrum. Ultrasonic piezo actuators vibrate in the 100 kHz range, far away from the audible spectrum. In contrast with the walking piezo, only one piezo element is used so a very compact design is possible. The lifetime of an ultrasonic piezo actuator can be up to km, about 100 times better than a stick slip system. Piezo actuators are available with an integrated closed-loop controller unit, so no external electronics are required. The travel range is virtually unlimited as the traveling rod can be cut at any length. Ultrasonic piezo actuators are the smallest high speed actuators available when a travel range of more than 10 mm is required.
Micro linear actuators are devices that use an electric motor to convert rotary motion into linear reciprocating movements. The working principle of the micro linear actuator is similar to a conventional linear actuator. However, due to its smaller size, it can be used in applications that have limited space. Micro linear actuators are important in modern technology. They play a role in precision control systems, such as robots and wearable devices.
The demand for micro actuators has increased due to the popularity of intelligent devices. This is especially true in applications that require precise control and low-power systems. These micro actuators can be used to meet the demands of intelligent devices, such as compactness, precision and reliability. They are also the core component of many advanced technologies and products. This article will give you the details.
In the field of robots, microactuators are crucial. This is especially true for service robots and in medical robots. They can be used to control robot movements, like the movement of a robotic hand or the displacement of mobile devices. Microactuators are essential components in small robots because of their compact design and high precision. This is especially true for tasks that require fast response times and precise positioning.
Wearable devices that require precise motion control are commonly equipped with microactuators. In smart watches, for example, microactuators are used to adjust straps or detect motion, while in medical devices, they can be used for fine positioning and adjustment. These small actuators are capable of providing efficient and stable operation, while using low power.
In the medical field microactuators are widely used, particularly in bed adjustments, positioning of diagnostic tools, and minimally-invasive surgical instruments. They are able to provide smooth, precise movements, enhance the treatment experience for patients, and meet high standards of medical equipment in terms of accuracy, reliability and low noise.
Microactuators are used in consumer electronics to adjust the focus and angle on headphones and projectors. The compact size and efficiency of this device makes it the perfect choice for this small gadget. It provides a convenient operating experience and flexible controls functions.
There are many factors to take into consideration when selecting a micro-linear actuator. The thrust is the most important factor to consider when determining whether the actuator will be able to carry the load. To ensure that the actuator is able to complete the required displacement, the stroke must match the application requirement. The speed requirements are based on the frequency and response time of the application. To improve efficiency, the right speed is chosen.
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To ensure compatibility with equipment and efficient operation, size and power should be adapted according to the space restrictions and power requirements. You should also consider the durability and accuracy of the actuator when selecting it to ensure stable long-term operation.
To ensure proper wiring, connect the controller and power supply before installing the micro actuator. Connect position sensors or limit switches to adjust the stroke and stop positions if necessary. Common problems during installation include overload protection which ensures that the actuator doesn't overload. Stroke limit settings are also important to ensure that the actuator doesn't exceed the range set.
Adjust the controller settings during commissioning to ensure the actuator operates accurately within the range predetermined.
Micro linear actuators are important in the Internet of Things and smart homes. They can be used to enhance automation and intelligence in equipment such as smart curtains, electric furnishings, and security systems. Micro actuators can be controlled by remote control and automated scripts when connected to IoT devices.
With technological advances, micro actuators continue to innovate, integrating functions such as sensors and feedback systems to improve accuracy and reliability. Enhanced load capacity and high efficiency enable them to adapt to more complex tasks, such as precise adjustment and high-frequency operation, promoting their use in a wider range of applications.
A high-speed micro linear actuator is designed to provide rapid linear motion in compact spaces. It typically features a fast-moving motor, optimized gearing, and efficient control systems, allowing for precise and quick actuation. These actuators are ideal for applications requiring quick response times, such as robotics, automation, and certain medical devices, where speed and accuracy are crucial for optimal performance.
Micro linear actuators are essential for precise, compact motion in applications like robotics, medical devices, and smart home systems. Their small size, low power consumption, and high efficiency make them ideal for space-constrained environments. For reliable, high-quality micro linear actuators, we recommend JIECANG, a trusted leader in advanced actuator solutions.
To make a micro linear actuator, you’ll need a small electric motor, a lead screw or worm gear mechanism to convert rotary motion to linear motion, and a housing for structural support. Attach the motor to a gear or screw that drives a sliding nut or piston. Add a controller for precise movement, and integrate sensors for feedback if needed. Ensure the components are miniaturized and efficient to achieve compactness and smooth operation.
The four main types of linear actuators are:
Electric linear actuators: Use an electric motor and a screw mechanism to generate linear motion.
Pneumatic actuators: Use compressed air to create motion.
Hydraulic actuators: Utilize pressurized fluid for powerful linear motion.
Mechanical actuators: Rely on mechanical systems like gears or cams to produce linear movement without external power sources.
Some miniature designs measure only a few microns. Micro linear actuators can, for instance, be as small as 10-20mm. They are often used in compact devices such as medical instruments, wearable technologies, and miniature robots. The size of the actuator is determined by the application, and the type motion required.
Typically, miniature actuators are powered by small DC Motors, piezoelectric Actuators, or small Solenoids.
The smaller the actuator is, the less force it can produce, which makes it unsuitable for applications that demand high load capacities. The use of advanced engineering techniques, including precision gearing, efficient power transmission systems and precision gearing, can allow for small actuators to perform well in specific applications, like precision control, or installations that require limited space.
Pneumatic cylinders are a cheaper alternative to linear motors. They use compressed air as their power source and provide a cost-effective way of generating linear movement. Solenoids offer another cost-effective option, particularly for simple, small-scale applications that need short strokes. Mechanical linkages and electric screw jacks are also suitable for situations in which high precision or force is not required.
Contact us to discuss your requirements of Micro Precision Linear Actuator. Our experienced sales team can help you identify the options that best suit your needs.