Omni Directional Multimaterial Soft Cylindrical Actuator and Its Application as a Steerable Catheter

Abstract

Soft actuators with complex range of motion lead to strong interest in applying devices like biomedical catheters and steerable soft pipe inspectors. To facilitate the use of soft actuators in devices where controlled, complex, precise, and fast motion is required, a structurally controlled Omni directional soft cylindrical actuator is fabricated in a modular way using multilayer composite of polylactic acid based conductive Graphene, shape memory polymer, shape memory alloy, and polyurethane. Multiple fabrication techniques are discussed step by step that mainly include fused deposition modeling based 3D printing, dip coating, and UV curing. A mathematical control model is used to generate patterned electrical signals for the Omni directional deformations. Characterizations like structural control, bending, recovery, path, and thermal effect are carried out with and without load (10 g) to verify the new cylindrical design concept. Finally, the application of Omni directional actuator as a steerable catheter is explored by fabricating a scaled version of carotid artery through 3D printing using a semitransparent material.

A Magnetically Controlled Soft Microrobot Steering a Guidewire in a Three-Dimensional Phantom Vascular Network

“…More recently, soft actuators made of various materials have been developed to steer catheters. 23 Eight deformations were programmed by using a microcontroller, and a 10-g load was used to evaluate performance. Further, a scaled version of a three-dimensional (3D)-printed carotid artery was utilized for steering.…”

3D printing for soft robotics – a review

“…(d) Demonstration of static steering of omnidirectional robot inside carotid artery. (e) Traveling of omnidirectional robot inside carotid artery [ 4 ].…”

“…The range of such materials has recently been extended to other soft materials and elastomers. The research group of Jennifer A. Lewis working on the applications of 3D printing technology has developed an omnidirectional technique with the ability to print extremely soft materials such as liquids that can be held in place through polymerization at a later stage [ 4 ]. The problem of providing a support material is well addressed while using the technique of photolithography for the development of soft structures as printing takes place inside a resin bath in which the unused resin can restrict the deflection of soft materials.…”

Status of and trends in soft pneumatic robotics

“…[122] . 但是由于硅胶浇筑成型中微小 气泡的存在会严重影响机器人的气密性和使用寿命, 所以浇筑前的真空除泡过程 [123] , 以及真空注模成 [126,127] . 虽然成型后的软体机器人结构可以 利用自身柔韧性通过变形进行脱模, 但是对于过于复 杂的结构, 脱模问题仍然是制造工艺中的难点.…”