Tuning electro-mechanical properties of EAP-based haptic actuators by adjusting layer thickness and number of stacked layers—a comparison

Abstract

In our fast-changing world, human-machine interfaces (HMIs) are of ever-increasing importance. Among the most ubiquitous examples are touchscreens that most people are familiar with from their smartphones. The quality of such an HMI can be improved by adding haptic feedback—an imitation of using mechanical buttons—to the touchscreen. Thin-film actuators on the basis of electro-mechanically active polymers (EAPs), with the electroactive material sandwiched between two compliant electrodes, offer a promising technology for haptic surfaces. In thin-film technology, the thickness and the number of stacked layers of the electroactive dielectric are key parameters for tuning a system. Therefore, we have experimentally investigated the influence of the thickness of a single EAP layer on the electrical and the electro-mechanical performance of the transducer. In order to achieve high electro-mechanical actuator outputs, we have employed relaxor-ferroelectric ter-fluoropolymers that can be screen-printed. By means of a model-based approach, we have also directly compared single- and multi-layer actuators, thus providing guidelines for optimized transducer configurations with respect to the system requirements of haptic applications for which the operation frequency is of particular importance.

The role of printed electronics and related technologies in the development of smart connected products

“…Focusing on PE, even though electroactive inks are already available, their mechanical strength and reliability still need to be improved. Notwithstanding, printing technologies, can already be used to deposit electroactive polymers (EAPs), and other electroactive materials such as ceramic and metal alloys (such as lead zirconium titanate and aluminum nitride) [250,251]. EAP can be dielectric (more used for low-frequency actuation applications) or ionic materials (used for high-frequency modulation applications) [250].…”

Flexible Vibrotactile Actuator Based on Dielectric Elastomer for Smart Handheld Devices

“…One of the most attractive methods for fabricating flexible vibrotactile actuators is the use of electroactive polymers (EAPs) [8][9][10][11][12][13][14]. Among EAPs, dielectric elastomers have many benefits, such as large displacement, moderate bandwidth, low power consumption, and low mechanical impedance compared to other electroactive polymers (ionic polymer metal composites, piezoelectric polymers, etc.)…”