Moisture responsive device and method

A method of detecting and/or responding to changes in moisture levels in situ in an environment comprising the steps of:

• disposing at least one moisture responsive device, wherein the moisture responsive device includes a moisture responsive element comprising at least a moisture responsive formation of a first material in association with a less moisture responsive formation of a second material, in that the first material has a greater tendency to absorb moisture and to increase in volume as a result than the second material, the two formations being so mechanically arranged together that such differential change in volume tends to cause mechanical deformation of the moisture responsive element;
• and an actuation member in mechanical association with the moisture responsive element so that deformation of the moisture responsive element in the presence of moisture tends to cause the actuation member mechanically to change between at least a first conformational state and a second conformational state and thereby cause the actuation member to change between at least a first functional state and a second functional state, in an environment as part of a system designed to monitor and/or control moisture levels in the environment;
• operating the system over time in such manner that as changes in the moisture levels actuate a change of state in the device, a response is generated in the system.

A method of controlling an irrigation system comprising providing an irrigation system comprising a network of irrigation hoses or the like fed from an irrigation fluid source or modifying such a network already existing in situ;

• incorporating into the network, in particular in the vicinity of one or more irrigation fluid delivery points, at least one moisture responsive device, the moisture responsive device comprising a moisture responsive element comprising at least a moisture responsive formation of a first material in association with a less moisture responsive formation of a second material, in that the first material has a greater tendency to absorb moisture and to increase in volume as a result than the second material, the two formations being so mechanically arranged together that such differential change in volume tends to cause mechanical deformation of the moisture responsive element;
• and an actuation member in mechanical association with the moisture responsive element so that deformation of the moisture responsive element in the presence of moisture tends to cause the actuation member mechanically to change between at least a first conformational state and a second conformational state and thereby cause the actuation member to change between at least a first functional state and a second functional state and further comprising a valve actuator so adapted as to tend to inhibit fluid flow in response to increased moisture levels;
• operating the irrigation system as desired by supplying irrigation fluid from the source to the network of hoses.