Prosthetic arms bend through a variety of mechanisms, often mimicking the natural movements of a human arm. A common method, particularly in biomimetic prosthetic hands, uses artificial tendons powered by technologies like liquid crystal elastomers (LCEs) and liquid metal (LM) heating elements.
Here's a breakdown of how this works:
- Artificial Tendons: Instead of biological tendons, these prosthetic arms utilize artificial tendons made of advanced materials.
- Liquid Crystal Elastomers (LCEs): LCEs are materials that contract linearly when heated. They act as the "muscle" in this system.
- Liquid Metal (LM) Heating Elements: LM elements are used to precisely heat the LCE tendons.
- Joule Heating: When an electric current passes through the LM heating element (Joule heating), it generates heat.
- Contraction: This heat causes the LCE tendon to contract.
- Movement: The contraction of the LCE tendon pulls on the prosthetic fingers or arm segments, causing them to bend, similar to how human muscles contract to move our limbs.
In essence, electrical energy is converted into heat, which then causes the artificial tendon to contract, resulting in movement. This allows for a relatively natural bending motion in the prosthetic arm. Other prosthetic arms may use different types of motors, pneumatics, or hydraulics to achieve similar results.
