Actuators Based on RFPs
Relaxor ferroelectric polymers (RFPs) can be utilized as haptic actuators with large strain rate and fast response time. Actuators based on RFPs provide tactile UI (haptic glove & suit) for a realistic user experience, improved task accuracy and efficiency in teleoperation, remote-controlled robots, and VR/AR/MR.
Working Principle
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Unlike conventional ferroelectric polymers, RFPs feature nano-sized polar domains, which result in a unique hysteresis curve.
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When a voltage is applied, it deforms rapidly in the direction of the electric field, and when the voltage is removed, it returns to its original shape.
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It provides vibration feedback by responding to the frequency of the applied electric field.
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InteractOn utilizes these RFPs to fabricate actuators.
Actuators Based on P(VDF-TrFE-CFE/CTFE) Terpolymers
InteractOn can provide actuators fabricated with ferroelectric P(VDF-TrFE-CFE/CTFE) terpolymers. The actuation of P(VDF-TrFE-CFE/CTFE) is based on the giant electrostrictive effect inherent to its relaxor ferroelectric nature. The actuation is driven by electrostriction, where the strain (S) is proportional to the square of the polarization (P), which is induced by the electric field (E). This leads to a large deformation that is directly proportional to E2. The physical mechanism involves the field-induced reversible transformation of molecular conformations and the alignment of PNRs, causing the material to contract in thickness and expand in area or length. These materials can achieve very high transverse electrostrictive strains (around 5-7%) while possessing a high elastic modulus (approx. 1 GPa), enabling them to generate both large displacements and significant forces.
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Key Advantages:
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Giant Electrostrictive Strain & High Force Output: The most distinctive advantage of this material is its exceptionally large strain of over 4–5% when an electric field is applied.
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High Energy Efficiency & Fast Response: Due to its inherent nature as a relaxor ferroelectric, the material exhibits very low energy loss (hysteresis loss) during electrical field cycling. This means that during repetitive operation, the actuator generates minimal waste heat and operates with high energy efficiency. It also responds very quickly to electrical signals, making it ideal for haptic feedback and soft robotics applications that require real-time, precise control.
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Exceptional Flexibility & Light Weight: The material is inherently soft and flexible, allowing it to be easily processed into films. This characteristic enables it to be perfectly conformed to curved surfaces, integrated into textiles, or shaped into complex 3D structures. It opens the door to new designs for flexible actuation systems that are unimaginable with traditional rigid and heavy motors or ceramic actuators.
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Enhanced Durability & Chemical Stability: The introduction of a third monomer (CFE or CTFE) into the P(VDF-TrFE) copolymer enhances its mechanical strength as well as its chemical and thermal stability. Its excellent resistance to moisture and a wide range of chemicals ensures long-term reliability in diverse operating environments.
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Major Challenge, "High Driving Voltage": The primary obstacle to widespread adoption is the need for very high electric fields (50-100 MV/m), which translates to high driving voltages (hundreds to thousands of volts) even for thin films. This poses safety concerns and complicates the design of driver electronics.
→ InteractOn possesses the expertise to fabricate multi-layer haptic actuators,
providing solutions that offer high power with low voltage.
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Primary Application: The foundational component for our Haptics for Electronic Devices & Haptics for VR/AR/MR