Seed Imbibition Monitoring Using Millimeter-Scale Wireless Sensing Systems

Imbibition can be thought of as the resultant of soil moisture, soil structure, and pericarp permeability. Accurate imbibition monitoring enables to characterize one of three by holding the other two constant. It helps scientists and farmers find better soil or genotypes by assessing biologically-available soil moisture. However, we now know that a previous imaging-based approach is not effective since it cannot take images through the soil. Accordingly, there is an urgent need to develop a tool to measure imbibition in soil in situ. Also, it is important that the new method should not disturb original imbibition behavior significantly. In this project, the PI will develop a millimeter-scale wireless sensing system with a seed holding structure that measures the growth rate ofa swelling maize seed in soil in situ and collects data wirelessly by a remote gateway. A maize seed is just an example. The developed technology can be applied to other types of seed with proper modification of a seed holding structure. The central hypothesis is that imbibition can be monitored by recording force generated by a single seed. The proposed approach digitizes resistance sensitive to force. Also, it minimizes an artificial impact on seed imbibition by minimizing form factor of the system based on die-stacked structure without discrete components. Once the system becomes available, we move one step forward for agriculture people to accurately evaluate their different types of soil or species based on measured imbibition