HalloWEB

Safe­ty pre­cau­tions

Warn­ing! Only un­der adult su­per­vi­sion.

Equip­ment

• Niti­nol coil;
• bat­tery pack with croc­o­dile clips;
• toy spi­der;
• pa­per clips.

Step-by-step in­struc­tions

Sus­pend a niti­nol coil above the ground and fix a toy spi­der to the free end. Stretch the coil down. At­tach the croc­o­dile clips of a bat­tery pack to the ends of the coil. The spi­der is climb­ing up!

Process de­scrip­tion

Niti­nol pos­sess­es a rare and amaz­ing prop­er­ty – the shape-mem­o­ry ef­fect. At room tem­per­a­ture, it de­forms eas­i­ly and read­i­ly adopts new shapes. But when heat­ed, it re­turns to its pre­vi­ous state, as if the met­al re­mem­bers how it was be­fore. Niti­nol is a con­duc­tor, so it can eas­i­ly be heat­ed with elec­tric cur­rent. In met­als, cur­rent is the or­dered move­ment of elec­trons. The run­ning elec­trons col­lide with the met­al atoms and ac­cel­er­ate their vi­bra­tions, which caus­es the met­al to heat up.

All the com­po­nents need­ed to com­plete this ex­per­i­ment can be found in the MEL Sci­ence sub­scrip­tion!