Bio-electricity

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1/30 Bio Electricity Testing

My goal for the thesis is to have the cut sunflower’s “dying process” as the main parameter and control of the piece.

To get the information of the state where the flower is in, I need to measure its bio-electricity signal while encountering excitement, which is light.

The testing setting are as the photos on the right, electronic signal monitored by oscilloscope.

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Components

• EMG electrodes pad + 10x probe
• RIGOL Oscilloscope 1000 series
• cut Sunflowers soaked in sugar water (approximately 1 week after cut off)
• Clip Light: 3PM5 LED Lamp </aside>

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Testing Results

p1-p2 ΔV : the waveform is from the difference of two channel. (in oscilloscope: A-B), and the ΔV is the absolute value of (Max-min) of this p1-p2 waveform

• Test 1. Noise Test Setting & Goal: Electrode p1 = p2 = A, no lighting. See if p1-p2 ΔV is close to 0. Result: ΔV = 120mV, it became more than 160mV after plugged into computer (Rmt state). Consider the bio-electricity is around a couple -10 mV, it will be hard to see the signal induced by light with 120mV background noise.
• Test 2. p1=p2 Light Test Setting & Goal: Electrode p1 = p2 = A, light on/off. See if p1-p2 voltage difference is close to 0. If not close to 0, see if light does activate different electrical response. Result: ΔV (lightoff)= 160mV, ΔV (lighton, either covered or not)= 620mV, ΔV (hairdryer)~ 160mV. It’s weird since it’s activated after the light is on but covered, and at the same time not really reacted to the high power high current hairdryer. I suspect that it’s because the PWM that the light is using. The result stayed the same even if I replaced the clip light with a LED panel light on battery.
• Test 3. Metal Sheet Test Setting & Goal: Electrode p1 = p2 = same point on metal sheet, light on/off. Since test 2 has a confusing result, I want to see if exchange the flower to a metal sheet will change the result. Result: ΔV (lightoff)= 32mV, ΔV (lighton, either covered or not)= 32mV. This experiment exchange test 2’s flower to metal sheet, to test if light has an effect on it, which it doesn't. Not sure what this means.
• Test 4. p1≠p2 Light Test Setting & Goal: Electrode p1 = A, p2 = B, light on/off. Result: ΔV (lightoff)= 88mV, ΔV (lighton, either covered or not)= 1.14V. The ΔV (light off) is smaller than p1=p2, ΔV (light on) is bigger than p1=p2. There’s more resistance since p1≠p2, so ΔV (light on) is expected, but what about ΔV (light off)? </aside>

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Conclusion

• The LED light’s power on make a difference (whether the light got covered or not), but hair dryer doesn’t.
• The flower’s electricity signal change when light is on, but the metal sheet doesn't behave the same.
• This approach is not suitable for measuring bio-electricity because of the massive noise. Office hour with Jeff to see if he can say something about it. </aside>

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Plant SpikerBox

This might be helpful, it’s made for measuring active potential, research a bit to see its performance in light

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Test 1,2,4

Test 1,2,4

Test 3

Light

This might be it