RenhotecIC Micro Vibration Motor - Small Body, Big Purpose

 

Micro vibration motors are generally installed in small handheld appliances such as mobile phones, toys, touch mice, beauty instruments, massage instruments, etc., and generate corresponding vibration feedback according to various situational needs. In recent years, with the rise of human-computer interaction technologies such as smart wear and virtual reality, simple visual and auditory feedback technologies can no longer meet people's needs for immersion and portability. s concern. The metaverse concept that has been popular in recent years will also bring unprecedented opportunities for the development of touch technology. Mapping and interacting the real world with the virtual world in large-scale game scenes through micro-vibration motors will bring gamers a better immersive gaming experience. With the continuous development of the Internet and virtual reality technology, micro vibration motors can also be used in telemedicine consultation, immersive game fire simulation training, military simulation training, police simulation training, etc. in the future, with broad application prospects.

 

Micro vibration motors mainly include rotor motors, linear motors and piezoelectric motors.

 

The rotor motor was first widely used as a mobile phone tactile feedback actuator. The rotor motor is composed of an eccentric metal block rotor on the motor shaft. The DC drives the eccentric rotor to rotate to generate centrifugal force. The ERM motor is constantly in an unbalanced state and generates vibration, thereby generating various vibration signals. A rotor motor uses electromagnetic induction to drive an eccentric rotor to rotate to generate vibration. The price of the rotor motor is relatively cheap, the manufacturing process is simple, and the volume is the largest among the three types of micro vibration motors. And the vibration start of the rotor motor is relatively slow, and there is no obvious sense of vibration direction. It is difficult to achieve quick start and stop, and the vibration feels a bit procrastinated. In the field of mobile phone applications, it is more common in low-end products. The early iPhone 4 used an eccentric rotor motor as the vibration motor of the mobile phone. The motor was thick and could not meet the needs of thinner and thinner smartphones. Apple began to use linear motors in iPhone 6 and later series of mobile phones and Apple Watch. Rotor motors can be used in applications where the ultimate cost performance is sought, such as toys.

 

Compared with the rotor motor, the vibration of the linear motor has a sense of direction. It is driven by alternating current and can output a peak voltage of up to 10V through the control chip. The energized coil is affected by the ampere force in the magnetic field and can generate an oscillating force in a single direction. . Short start-stop time, high vibration intensity, small size, long life, fast response, controllable vibration frequency and vibration amplitude, low power consumption, etc., and rich types of vibration signals. Linear motors have no friction and centrifugal force constraints during operation, can achieve high kinetic energy conversion efficiency in the transmission process, and can provide users with a better tactile experience in human-computer interaction. Currently, they are widely used in mobile phones, virtual VR, and video games. Controllers and other consumer electronics products.

A linear motor is a vibration motor that generates an oscillating force on a single axis, and drives a moving mass connected to a spring to generate the required vibration signal according to the tactile demand. According to the direction of its vibration stroke, it can be divided into longitudinal linear motor (Z axis) and horizontal linear motor (XY axis). The horizontal motor can achieve a longer stroke and a longer acceleration time, so the performance and price are higher than the vertical linear motor.

 

Piezoelectric Haptic Actuator (PHA) utilizes the positive and negative piezoelectric effect of piezoelectric ceramics. When ceramics are subjected to external pressure, the piezoelectric ceramic material will deform, and the internal polarization state of the material will change, thereby generating charges; When the piezoelectric ceramic material is loaded with a driving voltage, the ceramic material produces mechanical deformation and corresponding vibration.

Piezoelectric motors are different from ERM/LRA based on electromagnetic induction. Piezoelectric motors are composed of vibrating parts and moving parts. They do not have the windings, magnets and insulation structures of general motors. The power density can be much higher than ordinary motors, but the output power is limited. It should be made into a light, thin and short form.

The output of the piezoelectric motor is mostly low-speed and high-thrust (or torque), which can directly drive the load. Because there is no magnetic field inside this motor, the mechanical vibration frequency is outside the audible range, so it has little influence on external electromagnetic interference and noise. Compared with traditional motors, piezoelectric motors have the advantage of simple structure and high precision, and have broad application prospects in ultra-high-precision instrumentation, precision machinery, automation equipment, aerospace and other fields. However, piezoelectric ceramics are brittle materials with poor flexibility and brittle texture. If a mobile device equipped with piezoelectric ceramic actuators is broken, the piezoelectric ceramic actuators are also likely to be damaged.

 

Among the three types of micro vibration motors, linear motors have the best application prospect at present.