Overview
This lecture covers the definition, history, applications, and recent advancements of mechanical arms, including their roles in industry, medicine, and everyday life.
Definition and Components
- A mechanical arm is a machine that mimics human arm movements using beams, hinges, and actuators.
- One end of the arm is fixed; the other end holds a tool.
- Mechanical arms can be manually controlled or remotely operated (teleoperation).
- Computer-controlled mechanical arms are called robotic arms, a subset of all mechanical arms.
Historical Development
- Early prosthetics date back to Ancient Egypt and the late 1400s in Europe.
- Mechanical arms advanced during and after wars to help injured soldiers return to work.
- In the late 1930s, William Pollard and Harold A. Roseland developed a five-degree-of-freedom arm.
- The Unimate, invented by George Devol and marketed by Joseph Engelberger in 1961, was the first industrial robotic arm.
- The Stanford Arm (1969) could move through six axes and MIT's high-dexterity arm had twelve joints.
Industrial and Medical Applications
- Mechanical arms revolutionized automotive manufacturing (welding, die-casting) starting in 1962 at General Motors.
- Nachi’s 1979 motor-driven robot performed spot welding.
- Surgical robots began in 1985, with the FDA approving the da Vinci system in 2000.
- Johns Hopkins developed a prosthetic arm (2015) with 26 joints and 100 sensors, able to lift 45 pounds and sense texture.
Everyday and Special-Purpose Use
- Simple tools like tweezers and grabbers are forms of mechanical arms.
- NASA uses mechanical arms on space rovers for sampling and satellite maintenance.
- Law enforcement uses mechanical arms on robots for bomb disposal and hazardous operations.
Modern Advancements
- Artificial muscle tissue can lift up to 500 times its weight, enhancing arm strength.
- Sensor-enabled prosthetics connect to the spinal cord, restoring both movement and sense of touch.
- Lifelike prosthetic arms use artificial skin coatings to resemble real limbs.
Key Terms & Definitions
- Actuator — Device that moves or controls a mechanism or system.
- Prosthetic arm — Artificial limb designed to replace a missing arm.
- Teleoperation — Remote control of a machine or mechanical device.
- Degree of freedom — Number of independent movements a mechanism can perform.
- Spot welding — Welding process to join metal surfaces.
- Robotic arm — Programmable mechanical arm, often used in automation.
Action Items / Next Steps
- Review diagrams of mechanical arms and their components.
- Research advancements in artificial muscle and sensor technology in prosthetics.
- Prepare questions on the applications of mechanical arms in medicine and industry.