Abstract: This invention relates to a matric potential sensor (100). Specifically, but not exclusively, the invention may relate to a sensor containing micro-lattice matrix portions (104) arranged to take up water. The matric potential sensor (100) comprises sensing electronics (120) arranged to measure a change in a signal injected into a matrix via one or more sensing elements(102), wherein the matrix comprises at least one portion of a substantially open-cell hydrophilic micro-lattice matrix (104) arranged to absorb moisture from a medium into which, in use, it is inserted.