Fig. 8.
a Customized Ni conductor patterns on a PET substrate. b Relative resistance variation (R/Ro) with an increase in the temperature from room temperature to 440 °C. The inset shows a magnified view in the temperature range of 300–420 °C. c Measured R/Ro of Ni electrodes in tap water and seawater. The insets show the measured R/Ro values of the Cu electrodes in tap water (left) and seawater (right) (a–c reproduced with permission from Ref. [20]. Copyright Wiley–VCH, 2019). d Schematic of the monolithic LRS process. NiO NP ink is coated on a substrate via the doctor blading technique. Selective laser irradiation of the dried NiO layer using a computer-aided galvano-mirror system and a monolithic Ni-NiO–Ni structure having a NiO-channel (several tens of micrometers wide) formed via the simple hatching technique (d reproduced with permission from Ref. [109]. Copyright Wiley–VCH, 2020)