Illuminating an LED using your body as a conductor?

Discussion in 'The Projects Forum' started by jakemac, Feb 2, 2013.

  1. jakemac

    Thread Starter New Member

    Feb 2, 2013
    Hi guys, i'm not very knowledgeable in regards to cicuits and electronics, in fact i know just about nothing on the subject, but i need some help or just an answer to a pretty simple question.

    I'm a design student and i'm currently working on a project to create an educational, interactive installation to fit into the London science museum (It wont actually be used there, its just a theme for the assignment we were set), and i was hoping to create something about using the human body as a conductor.

    Basically, i had been told by one of my tutors that it could be possible to power an LED using just a 9v battery, a ball bearing touching the terminals and holding it in one hand. Then touching a piece of copper which is in turn touching an LED with your other hand, which should illuminate the LED. This may seem like a pretty miniscule sounding project at the moment, but it's just a section of a small prototype i'll be working on.

    Now i'm not particularly sure that this would work as i've asked others that i know who may have been able to give me a straight answer, but i've been hearing different things. So hopefully any of you guys can shed some light on my question, or maybe even suggest a better solution to this?

    Thanks in advance for any answers or suggestion. :)

    Also sorry if this thread is on the wrong area of the forum.
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    You can use a touch sensor, which works with capacitance.

    If you were able to put enough current to light an LED through your body from one arm to the other, it is called "electrocution".
    tshuck likes this.
  3. Markd77

    Senior Member

    Sep 7, 2009
    It might be possible, but I would recommend using two fingers on the same hand as that way there is no current travelling through the important bits of the body.
    I've seen slight light from an LED at under 1μA which could be possible through human body resistance:
    You would probably want to put it in a dark box because it's not going to be bright.

    Well-Known Member

    Mar 1, 2012
    35mA is all it takes to stop the heart.
  5. John P

    AAC Fanatic!

    Oct 14, 2008
  6. Markd77

    Senior Member

    Sep 7, 2009
    True, maybe less, but to get even 1mA the body resistance would have to be 9k ohms. I measure around 300k on my tongue with the probes 1cm apart although larger contact area would decrease that resistance.