Water Logic Gates Built at MIT 239
ndogg writes "This story is all wet. Paulo Blikstein at MIT has created a water computer. The one boolean logic gate he created functions as a half-adder (i.e. both XOR and AND). He then proceeded to create a four bit adder."
Wait for it.... (Score:5, Interesting)
I can't wait to see the references in the paper
Re:this is very old news... (Score:5, Interesting)
They have proven very useful in the medical field with respect to fluid logic ventilators, and possibly more sophisticated surgical equipment (aside from drills and saws which commonly are driven by compressed air). Many portable ventilators are commonly available which have no electronic parts to speak of and run on the pressurized air or oxygen that goes with the patient during transfer. More modern ones generate small amounts of electricity to power logic curcuits to achieve smoother or more configurable ventilation modes. Improving fluid logic to avoid this electronic dependency would be quite interesting whilst still keeping size down.
Just how water could play a part in ventilators escapes me, but such things as washing machines, dish washers and other appliances could benefit from not needing to use electricity.
I think the interest in this stuff, thankfully, goes beyond the cold war.
Bowdoin Water Adder (Score:5, Interesting)
http://academic.bowdoin.edu/computer-science/proj
Automatic Transmissions, Gate Fan-Out (Score:5, Interesting)
It's called fluidics, and it's decades old. It uses compressed air or water to create logic circuits.
Yeah, I think the only real innovation here is describing the gates by Boolean concepts. His other accomplishment is no moving parts - except, of course, the fluid, I was expecting check balls and things; his system would probably work extremely well under very controlled pressure conditions... but I can't imagine there's much tolerance for real-world conditions or capacity for fan-out from the gates. Having said that, it's still a neat project. Kinda like the digital alarm clock I'm building using nothing but relays.
Automatic transmissions have used hydraulic computers since their genesis in the late 1940s. Until electronically-controlled transmissions became widespread in the 1980s, automatic transmissions universally had a maze of check valves, pressure-operated cylindrical valves and diaphragms in order to select gear. It was called the valve body, and it is probably the most terrifying part of a car to have scattered across your workbench - orders of magnitude worse than even a California emissions 1983 Rochester Quadrajet. Inputs include selected gear, downshift linkage, engine speed, tailshaft speed. Outputs are a set of lines which are pulled "hi" (in pressure not voltage!) to engage bands on the outsides of planetary gearsets and therefore engage a given gear.
Absolute nightmare. But they worked quite reliably - the valve bodies, anyway. The transmission itself was sometimes another matter (see hydraulic-controlled GM TH-200, Hondamatic, etc.). Ford C4 and C6 were one of the few to have a valve body design flaw - in Park, accumulated pressure would engage the reverse bands, causing the familiar scene from Cops: a Ford product reversing in driverless circles until it hits something. Shut off the engine when you get out of the driver's seat, and set your parking brake.
Soooo old (Score:3, Interesting)
Fluidic technology has been explored for a backup computer for intrinsicaly-unstable aircraft, I'm not sure it's been deployed on any.
Bruce
Re:this is very old news... (Score:3, Interesting)
Re:this is very old news... (Score:3, Interesting)
from http://www.nanomedicine.com/NMI/9.2.7.6.htm [nanomedicine.com]
* In the 1950s, Marvin Minsky and Rollo Silver^289 built a "hydroflip computer" using hydraulic logic elements consisting of millimeter-wide grooves and holes in multiple layers of plastic sheets with small rods and balls inserted in some of the grooves. When the assembly was pressed together and connected to a water supply, it became a hydraulic computer powered by a 3-inch high column of water, operating at ~30 Hz.
289. Marvin Minsky, "Virtual Molecular Reality," in Markus Krummenacker, James Lewis, eds., Prospects in Nanotechnology: Toward Molecular Manufacturing, John Wiley & Sons, New York, 1995, pp. 187-195.
CC.
Oy. Mains. (Score:3, Interesting)
Night before the science fair he decided he needed a quick disconnect for the cassette interface instead of a permanent line. He figured the cheapest easiest solution on his bench was the lightweight AC extension cord, cut the middle and soldered the bare ends to the computer board and the cassette innards, leaving the plug/receptacle in the middle.
Guess which end was on the computer side? Guess what the first science fair judge did when he saw a dangling mains cord?