TECHNOLOGY FOCUS - ELECTRONICS - Preferred Composition: The conductive structure comprises at least one antenna, resistor, inductor, capacitor, diode, light-emitting element and transistor. The tag apparatus is a passive identification device having antenna configured to receive a radio frequency electromagnetic electrical signal. The detection circuit comprises voltage detection circuit, current detection circuit, photon detection circuit and electromagnetic signal detection circuit. The tag apparatus further comprises electrochemical energy storage device having negative electrode containing negative electrode redox-active polymer and positive electrode containing positive electrode redox-active polymer. The storage device further comprising an electrolyte layer interposed between the electrode layer (E1) and electrode layer (E2). The active tag device is an active radio frequency identification device tag.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The layer of redox-active polymer comprises hygroscopic additive chosen from chloride salt, sulfate salt, nitrate salt and organic salt.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The redox-active polymer comprises a structural group chosen from quinone, phenothiazine, N-functionalized phenothiazine, thianthrene, phenozine, phenoxazine, phenoxathiin, dihydrophenazine, dialkyldihydrophenazine, dibenzodioxin, benzofuran, benzodifuran, imide, phthalimide, N-substituted phthalimide, and their derivatives. The layer of redox-active polymer comprises a zwitterionic polymer unit configured to reversibly switch between zwitterionic state and non-zwitterionic state. The zwitterionic polymer unit is of formula (i)-(iv), preferably (v)-(x).W,W',X, X', Z and Z'=heteroatom chosen from oxygen, carbonyl, nitrogen, functionalized nitrogen and sulfur;M'=anion or cation chosen from sulfate, phosphate, phosphonate, carboxylate, ammonium, sulfonate, hydroxamate, trifluoroborate, acetate, imido, perchlorate, borate, nitro, halo, cyano, sulfonyl, cyanato, isocyano, sulfonium, phosphonium, carbanion and carborane;R,R1,R2=H, saturated or unsaturated linear or branched 1-6C alkyl or 1-6C ether;andn=repetition of subunits of respective structural group.