Haptic technology basics | How haptic technology Works

This page covers haptic technology basics and mentions how haptic technology based devices work. It mentions comparison between haptic actuator types viz. linear resonant actuator, eccentric rotating mass actuator and piezo haptic actuator.

What is haptics?

The word "Haptic" is derived from greek word "Haptikos" which means pertaining to sense of touch. Touch can result into many different physiological reactions. There are five senses viz. hearing, sight, taste, touch and smell. Out of these, touch is the most proficient. This sense is capable of providing simultaneous input as well as output.

About Haptic Technology:
• The term haptic technology or haptics refers to tactile feedback technology. This technology takes advantages of sense of touch by application of forces, vibrations or motions to user.
• The concept is enabled using haptic actuators which apply forces to the skin for touch feedback and controllers. The actuator provides mechanical motion as output to electrical stimulus as input.
• It has similar functionality as computer graphics does for vision.

The haptic technology based haptic devices are used in wide variety of applications viz. mobile, medical, education, industrial, commerce, sports, white goods, consumer, science, gaming, consumer devices such as cameras etc.

How Haptic Technology Works

how haptic technology works

We know that touch screens are replacing traditional user interfaces in various devices such as cell phones, tablets, laptops, desktops and portable gaming devices. This is due to the fact that haptics has many benefits such as incresed user satisfaction and more realistic experience. Moreover it improves task performance.

The figure-1 depicts the simple block diagram of how haptic technology works.
• As shown touch screen controller sends a trigger signal to the MCU or processor when a press is detected either using finger or hand.
• The 'touch event' triggers the MCU or processor so that it can generate the waveform as shown.
• This waveform is given as input to the driver IC which runs the vibrator. The waveform causes actuator to move in specific direction or pattern in order to create the vibration. Hence user will feel the sense of touch.

Comparison between haptic actuator types - linear resonant actuator, eccentric rotating mass actuator and piezo actuator

Following table mentions comparison between linear resonant actuator, eccentric rotating mass actuator and piezo actuator.

Following four factors are considered while selecting or purchasing haptic actuator or Haptic Sensor for your need.
• Bandwidth: Frequency range of effects it can produce or create.
• Response time: How fast it can produce certain effect.
• Mouting of haptic device: It affects origin of vibrations and how user perceives effects.
• Power Consumption: It depends on vibration duration and mass being moved.

Specifications eccentric rotating mass (ERM) actuator linear resonant (LRA) actuator piezo actuator
Vibration Source Motor Based and off center rotating mass is used. Motor Based; spring and magnet are used. Bending ceramic strip or disk is used.
Frequency 1 to 300 Hz 175 Hz 1 to 300 Hz
Response time 40 to 80 ms 20 to 30 ms less than 1 ms
Waveform DC voltage Sine wave Sine wave
Voltage 1 to 10 VDC 2.5 to 10 VDC 50 to 200 Vpp
Power About 10% of battery About 5% of battery About 7% of battery

Sensors and Transducers Related Links

Proximity Sensor
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temperature sensor
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Haptic Sensor

Also refer IoT compliant sensors which includes ambient light sensor, optical sensor, gesture sensor, proximity sensor, touch sensor, fingerprint sensor etc.

Refer Sensors and transducers article which covers types, basic functions and provide links to sensors and transducers. It include temperature sensor, humidity sensor, strain sensor, proximity or occupancy sensor, force or load sensor, voltage and current sensor, pressure sensor, speed sensor, resistance sensor, power sensor, level sensor, event or state sensor etc. One can also refer various tutorials available in "tutorial section" of RF Wireless world website.

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