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Mouser Electronics White Paper TDK Piezoelectric Actuators for Haptics Today, piezoelectric actuators for haptic applications are integrating these enabling technologies for enhanced performance and optimal user experience. Here are examples of the latest advances in this technology. PowerHap Actuators TDK PowerHap piezoelectric actuators are made with multilayer piezoceramics and mechanical displacement amplification, providing fast and precise displacement that is well suited to delivering crisp and sharp active haptics. Stainless steel bows are used in conjunction with the multilayer piezoceramic sections to augment the displacement of weighted sections far beyond the displacement of the piezoelectric sections. This arrangement results in vibrotactile and force feedback in a single device over a wide bandwidth of frequencies. With a range of frequencies and force outputs, these actuators can replicate a wide range of sensations with control of the frequency, signal characteristics, and signal strength. Moreover, applying pressure or vibrations to PowerHap devices generates signals that can be extracted from the device. A force sensor and vibrotactile or force feedback system in a single package allows for enhanced optimization with no additional cost or footprint. Example use cases include vibrotactile and surface haptics for automotive displays, accurate button- like feedback emulation for scientific and medical devices, compact tactile effects for wearable AR/VR, and enhancing the sensation of a stylus to mimic drawing with various tools. For quick haptics prototype design, TDK offers the PowerHap development starter kit. Featuring both seamless and round buttons plus additional PowerHap devices, the plug-and-play kit introduces engineers to incorporating haptic feedback into their designs. PiezoHapt Actuators TDK PiezoHapt actuators are thin vibrotactile devices composed of multilayer piezoelectric elements and a vibration plate. Their highly optimized design enables low-voltage operation, allowing for low power consumption. In addition to being highly efficient and compact, PiezoHapt actuators can provide near instantaneous, real-time response with an energization time that is a fraction of that of eccentric rotating mass (ERM) and linear resonant actuator (LRA) devices. A unique feature of PiezoHapt actuators is that they provide a much more uniform vibrotactile response than traditional vibrotactile technologies (Figure 6). This means that if a PiezoHapt actuator is mounted within a smartphone or wearable, the user will experience the vibrotactile response more uniformly across the display without extreme high spots and low spots. The unimorph structure, with ceramic piezoelectric elements bonded to a metal plate, allows for efficient vibrations by warping the plate into "mountain" and "valley" shapes when AC voltage is applied, enhancing tactile feedback. PiezoHapt actuators' multilayer design allows greater displacement at the same thickness as other vibrotactile technologies, enabling low-voltage operation (as low as 24V) with strong vibration performance. This design also eliminates solder joints, reducing stress and improving efficiency. Moreover, using more advanced control systems and multiple actuators, PiezoHapt actuators can deliver vibrotactile responses toward a targeted region or in response to interactive control algorithms. With a thickness of just 0.35mm, PiezoHapt actuators are easily integrated into slim devices with limited vertical headroom. Figure 6: The PiezoHapt actuator features a unimorph structure where ceramic piezoelectric elements with electrodes on both sides are bonded to one side of a metal plate. When an AC voltage is applied, the piezoelectric elements expand and contract, causing the metal plate to warp and generate vibrotactile feedback. (Source: TDK)

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