Flexinol Actuator Wire – 0.127mm (0.005″) Diameter (1 foot)
This 0.005″ Flexinol Actuator Wire (aka shape-memory Nitinol) is a one-foot long piece of nickel-titanium alloy that can flex and contract when a specific amount of heat or current is applied to it and are made specifically for linear actuators to replace small motors or solenoids.
If you are asking yourself “What sorcery is this?!” and you wouldn’t be alone! This isn’t magic, it’s just simple science thanks to shape memory and a change between the wires weaker, low-temperature form (martensitic) and its stronger, high-temperature form (austenite).
When the Flexinol wire is in its martensitic form, it can be formed and bent into different shapes. However, when an electrical current of ~320mA is applied to the wire or if it is heated to ~100°C it reverts to austenite form and recovers its previous shape with great force.
Additionally, you can anneal at ~500°C (use an industrial furnace or simply a lighter) it to whatever shape you would want, next once that current or heat is applied it will return to that new shape.
- Current Required for Austenite Form: 320mA
- Pull Force: 0.49 lbs (223 grams)
- Resistance: 1.9 ohms/inch (75 ohms/meter)
- Density: 0.235 lb/in3 (6.45 g/cm3 )
- Specific Heat: 0.20 BTU/lb * °F (0.2 cal/g * °C))
- Melting Point: 2370°F (1300°C)
- Latent Heat of Transformation: 10.4 BTU/lb (5.78 cal/g)
- Thermal Conductivity: 10.4 BTU/hr * ft * °F (0.18 W/cm * °C)
- Thermal Expansion Coefficient
- Martensite: 3.67×10-6/°F (6.6×10-6/°C)
- Austenite: 6.11×10-6/°F (11.0x 10-6/°C)
- Electrical Resistivity (approx.) Martensite: 32 micro-ohms * in (80 micro-ohms * cm) Austenite: 39 micro-ohms * in (100 micro-ohms * cm)
- Wire Length: 305mm (12″)
- Wire Diameter: 0.127mm (0.005″)
Video Introduction to Muscle Wire:
- These are the “HT” type wires.