Achieving superelasticity in additively manufactured NiTi in compression without post-process heat treatment.

Shape memory alloys (SMAs), such as Nitinol (i.e., NiTi), are of great importance in biomedical and engineering applications due to their unique superelasticity and shape memory properties.

Shape memory response of porous NiTi shape memory alloys fabricated by selective laser melting.

Porous NiTi scaffolds display unique bone-like properties including low stiffness and superelastic behavior which makes them promising for biomedical applications. The present article focuses on the techniques to enhance superelasticity of porous NiTi structures. Selective Laser Melting (SLM) method was employed to fabricate the dense and porous (32-58%) NiTi parts.

Mechanical and shape memory properties of porous NiTi alloys manufactured by selective laser melting.

Near equiatomic NiTi shape memory alloys were fabricated in dense and designed porous forms by Selective Laser Melting (SLM) and their mechanical and shape memory properties were systematically characterized. Particularly, the effects of pore morphology on their mechanical responses were investigated. Dense and porous NiTi alloys exhibited good shape memory effect with a recoverable strain of about 5% and functional stability after eight cycles of compression.

Conceptual design of a miniaturized hybrid local actuator for Minimally Invasive Robotic Surgery (MIRS) instruments.

The actuation mechanism of the tip of an endoscopic instrument is a major problem in designing miniature scale motorized instruments, especially when a high level of functionality and multi degrees of freedom (DOF) are concerned. We evaluated the different possible actuation methods for an endoscopic needle holder and proposed a new design of hybrid local-actuation, including a micro DC motor and a piezoelectric (PZT) actuator. The DC motor provided the long movement course required for opening-closing function of the gripper while the PZT guaranteed the high gripping force required for holding the needle.