Huizhou Pengchengrui Technology Co., Ltd.

Nickel titanium alloy (shape memory alloy, SMA) ropes can be used for robots and surgical instruments, but they have strict applicability scenarios and cannot be used casually.

✅  Conclusion: Yes, and it is already in commercial/scientific use, but it can be used in two ways

Nickel titanium alloy rope (multi strand twisted nickel titanium wire, Nitinol rope) has two uses: superelasticity and shape memory. Minimally invasive surgical robots and flexible continuous surgical instruments are very commonly used.

1. In surgical instruments/minimally invasive robots (most mature: super elastic nickel titanium rope)

>Not used as a 'memory driver', but as a tendon/transmission rope for flexible traction cables and serpentine arms

-Usage: Serpentine arm for single port laparoscopy, endoscopy, and flexible surgical robots, used as a push-pull traction rope to control end bending, biopsy forceps, grasping forceps, stone retrieval basket, and catheter guide wire; Orthopedic bundling steel cables are also nickel titanium ropes

-Advantages:

-Ultra large and super elastic: will not twist or permanently deform after bending (stainless steel cables are prone to dead bending and jamming)

-Resistant to repeated bending fatigue, suitable for thousands of bends in narrow cavities

-Medical grade (ASTM F2063) has biocompatibility, corrosion resistance, and can be sterilized with ethylene oxide

-Domestic example: The snake shaped arm of the surgical robot with a single hole, which extensively uses nickel titanium hyperelastic components as force transmission bones/traction cables; Beijing Institute of Technology's flexible surgical robot directly uses nickel titanium rope as a variable stiffness branch

>Attention: For implantation in the body, it must be medical grade nickel titanium. Ordinary industrial nickel titanium ropes cannot be directly inserted into the human body as there is a risk of nickel ion precipitation.

2. In ordinary robots (biomimetic, soft micro robots) (two uses)

1) Super elastic nickel titanium rope: used for transmitting tendons, similar to the one above, to make cables for flexible robotic arms and bionic hands, suitable for small volume and repeated bending scenarios.

2) Shape memory nickel titanium wire/rope: SMA artificial muscle (driver): electrically heated, alloy contraction pulling mechanism; After cooling, it elongates and resets, driven by temperature, without the need for motor gears, suitable for micro robots.

-Advantages: High energy density, small size, no noise

-Disadvantages: difficult temperature control, slow response, heat generation, limited cycle life, low load, generally only small force micro mechanisms are made, not suitable for heavy-duty industrial robots

⚠️  Key limitations (design must consider)

1. Shape memory driven nickel titanium rope: Fever problem, high risk of direct heating driven by medical body, and clinical instruments rarely use SMA memory effect for driving in vivo; Most of them only use its super elasticity as a traction rope.

2. High threshold for medical version: requires surface passivation treatment to control nickel precipitation; To conduct biocompatibility, fatigue, and sterilization verification, it belongs to medical device materials and cannot be made into surgical instruments by simply buying a nickel titanium rope.

3. Difficult processing and high cost; Very sensitive to pre tightening and heat treatment processes, once the heat treatment is done incorrectly, the superelasticity/memory characteristics will directly fail.

4. SMA drive (thermal contraction) has hysteresis, making it much more difficult to control than motor cables.

One sentence distinction

-  ✅  Super elastic nickel titanium rope: surgical robot snake arm traction rope, endoscope instrument cable, mature commercial use

-  ⚠️  Shape memory nickel titanium rope (electrically heated contraction): a miniature soft robot "artificial muscle" with many research prototypes, rarely used as a direct driver for surgical instruments inside the body

Pengchengrui Technology in Huizhou is a precision rope material source manufacturer, mainly engaged in seven strand twisted ropes, normal temperature and high temperature material ropes, and precision multi strand braided ropes, with an outer diameter of 0.3-1.2mm and strict control+0.05mm precision tolerance. We can provide reinforced braided layers for conduits, capture ring components, and high-end fishing gear consumables. The rope material is resistant to tension and bending, with stable quality, and can quickly respond to customized requirements for various precision components.