Active mechanical metamaterial unit cell with integrated piezoelectric stack actuator

Active mechanical metamaterial unit cell with integrated piezoelectric stack actuator

Saravana Jothi, Navin Shankar (TU Delft Mechanical, Maritime and Materials Engineering)

Hunt, A. (mentor)
Hassan HosseinNia, S. (graduation committee)

Delft University of Technology

Mechanical Engineering | Mechatronic System Design (MSD)

2021-11-09

Metamaterials are engineered structures that exhibit exotic properties that are obtained from the unit cell geometry and arrangement instead of its constituent materials. Mechanical metamaterials alter mechanical stimuli and they can exhibit unique elastic properties such as negative stiffness, shear modulus, bulk modulus, and Poisson’s ratio. Their mechanical properties are tailor-made to the application, and as a limitation they cannot be altered. Active metamaterials aim to address this shortcoming by integrating active transducers into the metamaterial design hence enabling it to actuate and control its properties in real-time. Active metamaterials could pave the way to a host of applications involving tunable properties. The objective of this work was to create a novel active metamaterial unit cell that utilizes commercially available piezoelectric actuators as its actuation method. A unique metamaterial unit cell structure to provide amplified output displacement has been realized, and experimental investigations were conducted to study their mechanical behaviour. The results show that the cell structure acts as a motion amplifier amplifying the input by 9.29 times, having a static deflection performance of 240 μm and a resonance displacement of 1510 μm at 81 Hz. The structure was able to transmit a fixed force of 0.3 N throughout the range of operating frequencies. This thesis project lays the framework for millimeter-scale active metamaterial unit cell structure for motion amplification.

Metamaterials
Active metamaterials
Mechanical metamaterials
Piezoelectric actuators

http://resolver.tudelft.nl/uuid:2eb4ae76-55e7-46f8-b960-7894f29df841

2023-11-09

Student theses

master thesis

© 2021 Navin Shankar Saravana Jothi