What's the best tactile feedback,refer to last article

http://www.coin-motor.com/mod_article-article_content-article_id-215.html

Piezoelectric tactile vs ERM tactile sensation

The acceleration in haptics is related to the intensity of tactile feedback you feel; The higher the acceleration that the actuator can achieve, the stronger the tactile feedback it generates.

The acceleration that the ERM system can achieve is quite limited, and the reason is easy to understand: the vibration motor needs to accelerate the mass to generate vibration. Therefore, it needs to break the mass inertia and increase the speed to the optimal frequency. However, the acceleration of the mass is not instantaneous, which is why the ERM motor emits a rumbling sound due to inaccuracy.

On the other hand, piezoelectric actuators have no mechanical limitations. Due to the fact that vibration does not rely on mass rotation, once high pressure reaches the piezoelectric material, the actuator will vibrate. Therefore, piezoelectric actuators can generate stronger and clearer feedback than ERM motors. In addition, taking Bor é as Technologies' piezoelectric CapDrive technology as an example, the ERM solution consumes 20 times more energy Power consumption: ERM vs. CapDrive technology piezoelectric tactile.

The main advantage of piezoelectric tactile technology in other fields is total power consumption. The performance of piezoelectric actuators is very high, but unfortunately, the low power consumption of the actuators is offset by the poor performance of piezoelectric actuators. The situation has changed since the release of CapDrive technology. The first piezoelectric tactile drive IC (BOS1901) using CapDrive technology is claimed to be the most efficient piezoelectric driver on the market. If you want to integrate touch control into devices with limited power consumption (such as mobile devices), piezoelectric tactile technology is a better choice than ERM solutions.

Piezoelectric almost instantaneous response, vibration motor response time is slower。

Tactile feedback requires perfect timing to generate the best feedback, and the faster the response time, the clearer and more accurate tactile feedback can be transformed. A vibrating motor requires a longer time to accelerate the rotational mass and reach its peak frequency (optimal feedback area); In addition, after achieving the effect, they need to slow down the quality. ERM usually takes up to 50 milliseconds (ms) to reach the peak frequency, and the delay in acceleration and deceleration will produce slight adverse vibrations at the beginning and end of reaching the peak.

The real-time response time of the piezoelectric actuator is less than 2 ms, which means you can hardly feel the slight adverse tactile feedback generated during acceleration and deceleration. Piezoelectric tactile feedback produces clearer and more accurate feedback, and the limiting factor of piezoelectric actuators is actually the response time of piezoelectric actuators. The response time of the BOS1901 piezoelectric driver is less than 6ms.

Piezoelectric tactile technology saves a lot of space compared to ERM systems.

Compared to piezoelectric tactile solutions, ERM vibration motor tactile systems are larger and occupy more space. Although ERM actuators are indeed smaller than piezoelectric actuators, the biggest difference lies in the size of the actuator. Piezoelectric actuators are smaller than ERMs and provide greater tactile feedback.

If you need a compact solution, piezoelectric touch is a better choice than vibration motors.

The advantages of piezoelectric effect.

The piezoelectric effect is reversible. You can apply high voltage to a piezoelectric material to make it move, but when the piezoelectric material deforms, it generates an electric charge. When you press the piezoelectric actuator, the piezoelectric material will deform slightly and the actuator will generate current. Piezoelectric drives using CapDrive technology can detect current, and they can detect pressure and trigger feedback from the same actuator.

The eccentric rotating mass tactile scheme can only trigger tactile feedback, so if pressure detection is required, in addition to the tactile system, a complete pressure sensing hardware system is also required.

This means that if you need a tactile solution that triggers when applying pressure (such as replacing mechanical buttons), you can cancel the sensing hardware and rely solely on one piezoelectric actuator and one CapDrive piezoelectric driver. This can significantly save space; This is what a SmartClik buttonless phone prototype does.

High resolution tactile technology vs. basic technology solutions

Piezoelectric actuators can produce more advanced tactile effects. Like speakers, they use electrical waveform signals from amplifiers (piezoelectric drivers) and can operate over a wide range of frequencies and amplitudes, producing various tactile effects. You can customize tactile feedback based on your application to create rich and detailed feedback. This is what we call high-definition tactile feedback.

On the other hand, the frequency range of ERM solutions is quite limited and cannot create the best feedback effect. This means that your tactile effect range is quite limited, and ERM motors are limited to low-quality applications.

Piezoelectric tactile technology brings the possibility of higher-level effects that ERM cannot replicate. 

Piezoelectric tactile technology is very suitable for various applications that require different tactile effects, such as AR/VR, vehicle safety alarms, button replacement, etc.

CapDrive Piezoelectric Tactile Technology vs ERM technology

------------------------------------To be continued---------------------------------