These experiments took place in the Summerlab organised by Ping at Nantes, from July 9th to July 11th, with Chiara Bedin, Etienne Maillard, Nadège and Matthieu Gonnet.

• Wiring as electrode.

• Peak voltage at 100mV, drops to 60, stable.
• Voltage changes with oxygenation - + 10 mV.

• Layed down the jar in a crate covered with a plastic bag and filled with water.
• Five times bigger cathode, made of wiring, and then replaced by a flattened aluminium can.

• Augemented cathode surface area & reduced water layer width for oxygen access.

• No improved voltage with bigger wiring cathode.
• Improved voltage (300 mV) with aluminium can cathode.
• When putting directly the multimeter cathode in water, we obtain 600 mV.

• The geometry of the multimeter cathode may be better for voltage than the one made of wiring or aluminium can. However, surface area is necessary to obtain current.

• Flattened aluminium can as electrode.
• Thick paper sheet as PEM.

• Reduced PEM width.
• Augmented electrode (both) surface area.

• Negative voltage when putting a rock on cathode to maintain it in water.
• No improved voltage by the new flat design.
• Still no current measurable, probably very low.
• The addition of coke drops (H+) at the cathode do not help current generation.

• Is paper a good PEM ?

• Two bottles
• Saline bridge made of rope dipped in salt solution & wrapped in tape.
• Hard-drive metal box as electrode material.

• The addition of coke drops (H+) at the cathode do not help current generation.

• Two multimeter electrodes directly in water: about 30 mV.
• One mutimeter electrode on aluminium can dipped in water, one directly in water: about 30 mV.
  • If water is not clean, voltage increases up to 100 mV.
• Two multimeter electrodes in the mud: 10-80 mV depending on location.

• Maybe it needs a longer period to get started - eating up all the oxygen around the anode.
• Maybe our PEMs are not good.