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posted by janrinok on Tuesday June 23 2015, @03:49PM   Printer-friendly
from the a-bright-idea dept.

Two high school students, Sum Ming Wong and Kin Pong Li, both living in Hong Kong have designed and built a door handle that kills germs, thus preventing the spread of disease through hand contact. They demonstrated their handle at the Intel International Science and Engineering Fair held last month in Pittsburgh—taking second place in the materials science category.

One of the ways that ailments such as cold and flu are passed is via contact, and one of the main avenues is via door handles—a sick person coughs into their hand then uses the handle to enter a bathroom, office, or other location, depositing germs. Others that enter the same room pick up the germs from the door handle and invite the germs into their own bodies by touching their eyes or noses. Door handles that kill such germs on contact would stop them from spreading—that is what Wong and Li set out to build.

The pair started by noting that a mineral called titanium dioxide is quite toxic to germs, but it hasn't been used as an antibacterial agent much because it requires the presence of UV light. To get around this problem, the team ground some of the mineral and then used it to coat a glass tube, they then affixed a LED onto one end of the tube—it shines UV light onto the insides of the glass tube—any germs that land on the outer side are then killed by the mineral (testing showed it to be 99.8% effective). Putting the glass tube onto brackets allowed for it to be used as a door handle.

Read More at PHYS.ORG

[Source]: Society for Science & the Public


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  • (Score: 0) by Anonymous Coward on Tuesday June 23 2015, @04:56PM

    by Anonymous Coward on Tuesday June 23 2015, @04:56PM (#199976)

    Door knob = $9
    Crash bar = $129

    But what's money got to do with it?

  • (Score: 0) by Anonymous Coward on Tuesday June 23 2015, @07:50PM

    by Anonymous Coward on Tuesday June 23 2015, @07:50PM (#200057)

    UV & titanium dioxide door knob & batteries = over $129

    • (Score: 0) by Anonymous Coward on Wednesday June 24 2015, @01:22AM

      by Anonymous Coward on Wednesday June 24 2015, @01:22AM (#200190)

      Titanium dioxide is commonly used to make white paint.
      You can get a gallon of really good paint for under $40.
      So, that doesn't seem to to be a major cost factor.

      A while back, for 99c (qty 1), I bought a flashlight with 7 LEDs.
      They are practically giving away LEDs these days.

      It's *batteries* that seem to be the big variable in this equation.
      What UV intensity is required? What duty cycle?
      How are you going to make them replaceable without making them easy to steal?
      What is the recharging mechanism?
      How do you get the juice from the door jamb to the door?
      How do you make that electrical path bulletproof (vandal-resistant)? [google.com]

      VLM mentions below the amount of schmutz that quickly collects on glass doors, forming a translucent layer.
      Is that schmutz opaque to UV?

      I'd like to see the results of some real-world tests on this concept.

      -- gewg_