The MIT associate professor of media arts and sciences is making prosthetic limbs and exoskeletons that restore function in those who have lost legs from injury or disease. This set of gifs focuses on his team’s BiOM powered ankle and foot prosthesis.
“Bionics is not only about making people stronger and faster,” he said during the talk. “Our expression, our humanity can be embedded into electromechanics.”
To prove his point, Herr and fellow researchers studied dance movement to replace the lower leg that professional dancer Adrianne Haslet-Davis lost after last year’s Boston marathon bombing. He concluded his talk by bringing Haslet-Davis on the stage to perform a bionic rumba.
Samuel Shian and David Clarke and their team at Harvard
University have designed a material that, with a shot of electricity, can
transform a glass window from transparent to opaque in less than a second! They
say this NSF-funded smart glass is cheaper
and easier to make than similar technology. We’re smart enough to feature their
podcast story on Science360 Radio: bit.ly/2aTLHYI
Image Credits: Samuel Shian, Harvard University
Above: Samuel Shian and David Clarke holding up a sample
Pulse Machine is a unique electromechanical sculpture that was created by Alicia Eggert and Alexander Reben.
This electromechanical sculpture was ‘born’ in Nashville, Tennessee on 2 June 2012, at 6:18 PM. It has been programmed to have the average human lifespan of babies born in Tennessee on that same day: approximately 78 years. The kick drum beats its heartbeat (at 60 beats per minute), and the mechanical counter displays the number of heartbeats remaining in its lifetime. An internal, battery-operated clock keeps track of the passing time when the sculpture is unplugged. The sculpture will die once the counter reaches zero.
The MIT School of Architecture’sSelf-Assembly Lab has teamed up with Google to create Transformable Meeting Spaces, a project that utilizes woven structure research in wood and fiberglass pods that descend from the ceiling, transforming a large space into a smaller one. Designed as a small-scale intervention for reconfiguring open office plans—which “have been shown to decrease productivity due to noise and privacy challenges”—the pods require no electromechanical systems to function, but rather employ a flexible skeleton and counterweight to change shape. Via
Electrical and Electronic Systems: Electromagnetic Systems
Drive in many mechanical systems provided by electric motors, which are electromagnetic devices.
Magnetic fields are established around any current carrying conductor.
By convention it is assumed that a magnetic field circulates clockwise around a conductor carrying current into the page and anticlockwise around a conductor where the current flows out of the page. This is the right hand screw rule.
Solenoid - if a current carrying conductor is would into a cylindrical solenoid, magnetic field around each conductor merges to produce a field pattern associated with bar magnets. Right hand screw rule is used to find direction of field through the centre of the solenoid.
Toroid - magnetic field associated with both single conductor and solenoid are non-uniform and difficult to calculate. Toroid = closed system, ring shaped core of magnetic or non-magnetic material wrapped with a conducting coil insulated from the core. Current flows in coil, uniform magnetic field is established and circulates around the ring core.
Flux density = Flux/Cross-sectional Area
Magnetic Force = Current x Number of turns in coil
Flux = Magnemotive Force/Reluctance
Resistance = Resistivity x Length / Cross-Sectional Area
Reluctance = Length/(Permeability of Core x Cross-Sectional Area)
Magnetic Field Strength = Magnemotive Force/Length
Flux Density = Permeability of Core x Magnetic Field Strength
In circuits with non-magnetic material, Flux Density and Magnetic Field Strength have a directly proportional relationship.
Electromagnetic induction - wind two coils on a toroid, connect one through a switch to a battery, and the other wired to a galvanometer, which is used to measure small voltages. When switch is closed, galvanometer needle deflects and then returns to zero. When the switch is opened, the needle moves in the opposite direction before going back to zero.
From his experiments Faraday was able to deduce that the magnitude of the emf, e, induced in the coil - as measured by the galvanometer - was proportional to the rate of change of magnetic flux linkages with the coil.
emf = Number of turns x change in instantaneous flux / change in time
emf = inductance x change in current/ change in time
The emf induced in a coil is equal to its inductance multiplied by the rate of change of the current flowing through it.
Mechanical Work done to move the conductor = force on the conductor x distance moved by the conductor
Part of a panel switch, Franklin Exchange, Chicago, Illinois, 1938. Dozens of vertical rods are visible on the panel banks. These rods assume various positions, and they move considerable distances to make the appropriate contacts for the call being connected. This is only one section of the complete switch, which, like all large electromechanical telephone switches, filled much of the telephone exchange building.