BioMetal® Helix - SMA coils providing greater changes in length

BioMetal Helix Includes one SMA coil spring 20 mm long (in contracted state), made from 150 µm diameter BioMetal shape memory alloy wire, 4 spectacle terminals, 4 eyelet terminals, instructions. According to the manufacturer this material will stretch up to 3 times the compressed or powered length- i.e. the 20mm length will increase up to 60mm maximum. Specs for 050, 20mm Helix (Item #3-912, SRP $28.95): Coil outside diameter: 0.20 mm Diameter of wire: 0.050 mm Weight liftable on recover: 3 grams Total resistance: 75 ohms Typical activation current at 20°C: 40 mA Specs for 100, 20mm Helix (Item #3-925, SRP $26.95): Coil outside diameter: 0.40 mm Diameter of wire: 0.100 mm Weight liftable on recover : 12 grams Total resistance: 27 ohms Typical activation current at 20°C: 80 mA Specs for 150, 20mm Helix (Item #3-922, SRP $26.95): Coil outside diameter: 0.60 mm Diameter of wire: 0.150 mm Weight liftable on recover: 30 grams Total resistance: 7.5 ohms Typical activation current at 20°C: 150mA