Title: Deformation of planar bending shape memory alloy-based soft actuator with cantilever bending and torsional tip load

Authors: Leong Shii Jang; Dayang Laila Abang Abdul Majid; Ermira Junita Abdullah; Faisal Abdul Hamid; Husam Yahya Imran

Addresses: Department of Aerospace Engineering, Faculty of Engineering, University Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia ' Department of Aerospace Engineering, Faculty of Engineering, University Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia ' Department of Aerospace Engineering, Faculty of Engineering, University Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia ' Department of Aerospace Engineering, Faculty of Engineering, University Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia ' Department of Aerospace Engineering, Faculty of Engineering, University Putra Malaysia, UPM 43400 Serdang, Selangor, Malaysia

Abstract: Soft actuator using shape memory alloy (SMA) as a smart material, has exhibited exceptional capability to undergo large deformation when activated. SMA wire positioned at neutral plane of soft matrix have presented load gripping capability for example pick and place where the load is in series. However, planar bending actuators have been reported not capable in sustaining large cantilever tip load while actuating. In this paper, cantilever Thermoplastic polyurethane (TPU) matrix with SMA wire through 3D printed aperture eccentrically from the neutral plane (top, mid and bottom) along the length of the actuator is proposed. Comparing to TPU without SMA, inactive SMA has increased the flexural rigidity of the structure to resist bending load and torsional load about 38%-40%. Reverted S shape deflection of activated SMA is proven by the overall tilted bending moment. Furthermore, torsional load rather than bending load has exhibited 5%-42% lower deflection along the sample length.

Keywords: shape memory alloy; SMA deflection; soft actuator; 3D printing.

DOI: 10.1504/IJMATEI.2026.153163

International Journal of Materials Engineering Innovation, 2026 Vol.17 No.2, pp.91 - 103

Received: 30 Sep 2022
Accepted: 15 Dec 2022
Published online: 25 Apr 2026 *

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