Method 700 commences at step 702. Step 702 comprises dissolving the acrylic acid (AA) and sodium chloride (NaCl) into deionized water in an ice bath. In this example the amount of AA is 5.1M and the amount of NaCl is 4M. The ratio of AA to NaCl is between 1.2 to 1.3 and preferably around 1.275. Step 704 comprises adding the APS or another thermal initiator into the solution. The amount of thermal initiator is approximately 0.0015 the weight of the AA. Step 706 comprises adding the MBAA or other cross linker. The amount of cross linker is approximately 0.0005 of the weight of the AA. Step 708 comprises stirring the mixture for at least 30 minutes. Step 710 comprises degassing the stirred mixture in a vacuum chamber. Step 712 comprises pouring the solution into moulds. The moulds are shaped to correspond to the desired shape of the electrodes. The moulds may be made of glass or any other suitable material. Step 714 comprises curing the solution within the mould at a predetermined temperature for a predetermined time. In this example the set temperature is 70 degrees Celsius and the set time is 40 mins. Curing results in the creation of a hydrogel that is ionically conductive due to the mixed salt (i.e. NaCl). Step 716 comprises placing the cured hydrogel into a humid box for 60 hours to stabilize the reaction. Step 718 comprises cutting the hydrogel into a desired shape e.g. to form two electrodes. Steps 610 and 620 comprise the method 700 to form the first electrode and second electrode.