Induced twist in geometrically incompatible bi-layer tubes

events hall

Ms. Kristina Bazaev - M.Sc. Candidate

03/11/2024

אודיטוריום ע"ש דויד וואנג, בניין מידן, קומה 3

14:30

Twist-actuated devices are essential in soft robotics and actuator applications; however, conventional approaches typically require direct torque application. Recent studies present a novel approach to creating controlled twist motion without the need for applied mechanical torque.

In this seminar, I will present my research on a polymeric-based bi-layer tube designed to achieve a twist upon external stimulation, which can be used as a torsional actuator. The bi-layer tube consists of a twisted inner layer and an outer layer, adhered along the interface, resulting in residual stress within the bi-layer and deformation-induced anisotropy. This configuration enables the tube to twist in response to external stimuli.

We propose a model for the electro-mechanical response of induced twist in a bi-layer tube structure using theoretical modeling and numerical simulations. We employ the Gent hyper-elastic model for a Dielectric Elastomer (DE) –based bi-layer tube and examine how varying material and structural parameters, including radii, stiffness, permittivity, and lock-up stretch, affect the twist response under electric excitation. The findings contribute to the theoretical understanding of DE-based actuators and open new pathways for designing responsive materials for advanced engineering applications, including soft rotational robots, artificial muscles, and soft torsional actuators.

Supervisor: Assoc. Prof. Noy Cohen