Self-writing smart labels employing ambient water harvesting

Lateral anodic oxidation is a recent display technique with potential utility in the development of self-writing smart labels. This process requires water for activation, and the labels are typically operated at elevated humidity. To increase the operating humidity range of labels based on this mechanism, we incorporated a thin water harvesting layer to extract the necessary water from the ambient atmosphere. We examined the effect of relative humidity on the display process for several types of water harvesting layers. Labels based on lateral anodic oxidation of aluminum could be successfully operated under relative humidity down to 11% and the overall dependence of the devices on the relative humidity was reduced.