In Journal of Laser Applications, researchers present paper-based temperature and humidity sensors that are accurate, reliable, and eco-friendly. The team created the sensors by printing silver lines on commercially available paper through dry additive nanomanufacturing. As the paper absorbs water vapor, its capacitance change is measured to reflect the relative humidity of the environment, and as the temperature increases, the metallic conductor experiences an increase in resistivity. They successfully detected changes in relative humidity levels from 20% to 90% and temperature variations from 25 C to 50 C.

Most batteries are rigid and incompatible with water. But people work and play in oceans and estuaries, and they could benefit from flexible and saltwater-safe power sources. Now, researchers report in ACS Applied Materials and Interfaces a yarn-like battery prototype that works when immersed in seawater. They knotted the rechargeable strands into a fishing net that lit up LEDs and wove a fabric that powered a timer.