To help farmers irrigate their crops more efficiently and save water, Yoshihiro Kawahara, an Associate Professor in the department of Information and Communication Engineering at The University of Tokyo, developed paper-printable sensors that provide real-time measurements of soil moisture.
Kawahara worked with researchers from Georgia Institute of Technology and MIT Media Lab to develop SenSprout, an affordable device powered by radio waves in the air. Kawahara wanted to create an affordable device so he decided to make it out of paper. He was able to find a way to print an electronic circuit using silver nanoparticles.
SenSprout can be printed out using a standard ink jet printer. The sensors and antenna are printed directly onto the node using commercially-available ink that contains 20-nanometre-long silver particles. The antenna converts radio waves in the air into DC current.
Kawahara intended to make the device affordable for farmers and he thinks that in the future farmers will be able to download their own sensors and be able to grow their crops efficiently.