Soil Moniroting - Liquidentity

Background:

For much of farming, accurate soil monitoring is essential. Yet, standard water content sensors based on capacitance ($1k), time-domain reflectometry ($4k) and Neutron probes ($10k+) have prohibitive cost for much of the world, meaning a massive hit to crop yeilds.

Graphene Background

Graphene, a single layer of carbon atoms garnered immense interest due to its electrical, thermal, and mechanical properties. However, its potential has yet to be fully realized and it is looking for use cases. We were inspired by these two papers Will Any Crap We Put into Graphene Increase Its Electrocatalytic Effect? and DFT Studies of the Interactions of a Graphene Layer with Small Water Aggregates . These suggest that the density of states of graphene is changing when in water (even at very small (atomic) concentration) is present.

Soution

We made a minimum viable protype in less than 24 hours and won the hackathon and won £5k to develop the idea (covid then hit and project died), but the idea was effectively a 3 point probe with graphene interlayers, you put soil inbetween the probes and it worked! Giving a change in resistivity as a function of soil moisture content.

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