Microtentacle Actuators Based on Shape Memory Alloy Smart Soft Composite

Abstract

Recent advances in miniature robotics have brought promising improvements in performance by leveraging the latest developments in soft materials, new fabrication schemes, and continuum actuation. Such devices can be used for applications that need delicate manipulation such as microsurgery or investigation of small-scale biological samples. The shape memory effect of certain alloys is one of the promising actuation mechanisms at small scales because of its high work density and simple actuation mechanism. However, for sub-millimeter devices, it is difficult to achieve complex and large displacement with shape memory alloy actuators because of the limitation in the fabrication process. Herein, a fabrication scheme for miniaturized smart soft composite actuator is proposed by utilizing two-photon polymerization. The morphing modes are varied by changing the direction of the scaffold lamination. In addition, the actuation is controlled via local resistive heating of a carbon nanotube layer deposited inside of the actuators. The proposed design can generate a 390 µN force and achieve a bending angle up to 80°. Applications of the actuators are demonstrated by grasping small and delicate objects with single and two finger devices.

Design of a SMA-based soft composite structure for wearable rehabilitation gloves

“…Shape memory alloys embedded composite structure, which is known as smart soft composite structure has been studied to achieve a larger bending displacement and complex motions (Lee et al, 2020). SMA-based soft composite structure (SSCS) has been favored by many scholars in the research of bionic robots because of its good mechanical performance, programmable drive and multiple driving dimensions (Kim et al, 2012;Rodrigue et al, 2017;Lee et al, 2019).…”

A Multifunctional Reconfigurable Absorber Enabled by Graphene and Shape Memory Alloy

“…[40] The SMA spring adopted in our absorber is a stretching-type helical structure, which is generally exploited as an electromechanical actuator. [41,42] As Figure 2a shows, the employed SMA spring is temperature-dependent and its length can be stretched or compressed with the temperature variation. However, temperature control is difficult to be implemented in practice, and thus the whole SMA spring was evenly coated with the conductive silver paste, which could restore and retain their deforming length through the external bias voltage.…”

Surgical Robotics: Towards Measurable Patient Benefits and Widespread Adoption

“…1 Notable examples are in the field of soft robotics, with new materials (electroactive polymers [28], metamaterials [29] and hydrogels [30]), new structures (steerable needles [31], continuum robots [32], granular jamming [33], [34]), new surgical phantoms [35], [36], and new sensors and sensing schemes (Fibre-Bragg-Grating-based shape sensing [37], bioimpedance tomography [38], fibre-based Optical Coherence Tomography [39], Optical Doppler Flowmetry [40]), and miniaturization, a field that is still in its infancy, but that holds significant promise for the future of patient-specific, non-invasive medicine. As an example, research teams at the Hamlyn Center (Imperial College), supported by the EPSRC's Microengineering Facility for Robotics, are developing a new class of tethered and untethered microscale (grippers [41], micro-tweezers [42], microbots [43]) and nanoscale [44] robots that enable autonomous and remote manipulation of cells and drugs. These new technologies are still in their infancy, but will eventually lead to localised treatment as well as targeted delivery of therapeutics for personalised and regenerative applications.…”