If you’re a farmer with a herd of hundreds of cows, keeping tabs on their whereabouts and wellbeing can be challenging work, but we’ve seen how sensor tags might one day ease the burden. New research has taken this concept in an interesting, self-sustaining direction, demonstrating how smartwatch-style sensors strapped to cow ankles and necks can power themselves through the animals’ movements.
Some sensors and tags are already used to help monitor the location of cattle, to prevent them wandering too far. But scientists at Southwest Jiaotong University in China have explored the idea of a “smart ranch,” where advanced sensors would monitor the environment and the animals themselves, and be powered largely by kinetic energy.
"On a ranch, monitoring environmental and health information of cattle can help prevent diseases and improve the efficiency of pasture breeding and management," says co-author Zutao Zhang. "This information can include oxygen concentration, air temperature and humidity, amount of exercise, reproductive cycles, disease, and milk production."
In the team’s hypothetical smart ranch, cows would wear a smartwatch-like wearable shaped like a scallop shell. The shell moves in-synch with the animals’ body, while a pendulum inside swings around and works with magnets and coils to amplify these movements and turn the kinetic energy into electrical energy, which is stored in an onboard lithium battery.
"There is a tremendous amount of kinetic energy that can be harvested in cattle's daily movements, such as walking, running, and even neck movement," says co-author Yajia Pan, an energy researcher at Southwest Jiaotong University.
The team tested out the energy-harvesting potential of the device in lab tests that simulated movements of cattle, and proved that it could generate enough power for small sensors. The scientists also tested the device on humans and found that a light jog was all that was needed to power a temperature-measurement function.
"Kinetic energy is everywhere in the environment – leaves swaying in the wind, the movement of people and animals, the undulation of waves, the rotation of the earth – these phenomena all contain a lot of kinetic energy," says Zhang, "We shouldn't let this energy go to waste."
The research was published in the journal iScience.
Source: Cell Press via Phys.org