Slashdot Mirror
Sticky Tape Found To Emit Terahertz Radiation
An anonymous reader writes with this excerpt from New Scientist "'Peeling sticky tape has already been shown to produce X-rays, so Joseph Horvat and Roger Lewis of the University of Wollongong in New South Wales, Australia, tried to see if it could create lower-frequency terahertz radiation. "We were rather pleasantly surprised to obtain a clear signal in our first attempt," says Horvat. Strongly adhesive Scotch Magic 810 tape and weakly adhesive electrical tape both yielded strong terahertz signals, ranging from 0.1 to 10 terahertz, but only about a microwatt of power, too little for practical use (Optics Letters, vol 34, p 2195). Horvat says that refinements should increase the power by orders of magnitude.' It may be old news to Slashdot that [peeling clear tape] had been proved to produce X-rays, but watching the linked video where they use tape to expose X-ray film was pretty amazing."
From now on, it's staples for everything.
Yes, you will have the power to mend small tears in sheets of paper. The magical ability to control paint to be applied in some areas but not in others along nice sharp lines. The super human ability to stop electricity from shorting between two wires.
Among other similar powers.
Paying taxes to buy civilization is like paying a hooker to buy love.
If anyone is curious about how this happens, it is due to the very high voltages developed on clear sticky-tape when it is unrolled. The peeling action tends to create a very uneven distribution of charges on the tape surface... the tape itself is a wonderful insulator, and as a result the charges cannot easily snap back to equilibrium states.
:-(
This causes very high voltages and, where the tape is just being unrolled from the roll, extreme electric field as the distance is so small. (Remember, Electric field is measured in V/m!). Charges arc through the air easier than they can travel through the tape, so you get all sorts of emissions from this miniature lightning storm as the voltage drops back to a static level of 'only' about a kV.
Incidentally, this is why you should always use special ESD-approved tape when working anywhere around electrostatic-discharge-sensitive devices. My company's ESD training class had some quite interesting demonstrations where stuff was destroyed with a single piece of freshly unrolled tape. Unfortunately for me, I had yet to learn that lesson in graduate school, and so I ruined many a sensitive analog ASIC by taping a supposedly protective dust cover over the bare IC* (we were too cheap to pay for the black packaging that most people call a "chip").
*Note to all the pedants out there: Yes, a fabricated IC has its own natural shield of silicon dioxide (glass) on top of the deposited layers, however the tens-of-micron-thin wire bonds that connected the IC to my prototyping board were exposed to air, and could easily be broken--or worse, shorted--by errant dust particles.
>> Standing on head makes smile of frown, but rest of face also upside down.