With the success of smartphones, touchscreen technology using haptic feedback has become mainstream. Innovative user interface concepts go a step further and use haptic or vibrotactile feedback in order to give touchscreens a unique feel and user experience. Haptic feedback can make operation significantly easier and more intuitive, for instance, by letting the user know through haptic feedback which virtual button is under their finger or whether it was successfully activated. Laser vibrometers provide non-contact haptics testing solutions for the continuing research, development and quality control of haptic feedback, haptic displays and other haptic devices based on vibration, ultrasound or surface waves.
Typical haptic applications and technologies
The adoption of haptic interfaces in consumer electronics as well as in automotive applications has seen rapid growth, also giving a boost to developing haptic technologies which feature novel capabilities like localized haptic feedback for surface haptic devices and mid-air haptics. With surface-haptics, which is most commonly employed, haptic feedback is transmitted by a surface, e.g. a virtual button on a touchscreen which upon pressing creates a haptic cue in form of a vibration signal. The second, but less known field of mid-air haptics generates haptic sensations in free space which has the potential to revolutionize immersive experience in virtual reality applications. Most technologies – surface-based and mid-air haptics alike – use either low frequency mechanical vibrations (vibrotactile motion) or ultrasonic vibrations for direct generation of the haptic feedback or energy transmission from the actuator to the target location.
The haptic feedback needs to be quantified and localized for haptics performance verification and FE model validation of haptics devices. For haptics transducer array characterization and for mid-air sound-field characterization, also known as refractro vibrometry, use non-contact vibration measurement solutions. Visualize relevant haptic feedback technologies for comprehensive characterization of your haptic devices.
Laser vibrometers are instruments for non-contact haptics testing based on laser interferometry commonly used in R&D and quality control throughout all kinds of industries. Laser vibrometers are perfect for haptic testing precisely characterizing the dynamics of haptic devices. By measuring non-contact they avoid any mass-loading onto a sample end hence capture the true and undisturbed sample motion and haptic feedback. For haptic technologies based on ultrasound, laser vibrometers easily cover the typically operating frequencies of tens of kHz. The µm-sized laser spot size leads to a high spatial resolution, which allows resolving short wavelengths of ultrasonic wavefields.
Both 1D and 3D motion data gathered in a non-intrusive way using laser vibrometers precisely describe the in-plane and out-of-plane vector components enabling a full characterization and visualization of the haptic signature at R&D stage. In production testing, laser vibrometers from Polytec help assure the desired haptic feel reliably and with laser precision. See the measurement setup of a haptic panel mounted vertically in front of a 3D laser Scanning Vibrometer and a second vibrometer mounted above the haptic panel capturing the actuator’s motion through a small opening in the housing as phase reference. The resulting measurement data shows the time traces for the selected measurement point on the haptics panel. Three time traces are displayed for x, y and z directions independently.
Haptic feedback makes users comprehend functions and commands by giving a haptic cue removing the need to look on a display or control panel. This haptic feedback is generated by actuators or transducers and acts as an information carrier. Advanced haptic technologies can also reproduce the feel of physical texture on screens in real-time, creating deep, immersive experiences. One of the innovators in the field of haptic display development and using haptics for enhanced user experiences and control panels is Hap2U.