Tomorrow’s ranchers may be able to monitor their animals’ health from the comfort of their home—and completely off the grid. By attaching small, pendulum-based devices to the ankles of cattle, Chinese researchers believe they’re one step closer to developing self-powered “smart ranches.”
“There is a tremendous amount of kinetic energy that can be harvested in cattle’s daily 9movements, such as walking, running, and even neck movement,” Zutao Zhang, a co-author of the research and an energy researcher at Southwest Jiaotong University in China, said in a press release. Harnessing this untapped energy source can then power wireless sensors on cattle that can inform a rancher about their herd’s health.
After building a prototype, the researchers attached it to a motor-powered crank that mimicked a cow walking. The shell wearable produced an average power of 7 milliwatts and required a frequency of 2 Hertz—more power with a lower frequency of back-and-forth motion than previous studies’ designs for kinetic energy harvesters, meaning the new device is more efficient and better adapted to real-world conditions.
Of course, the study wouldn’t be complete without hooking the device up to a bovine experimental subject. A cow wore the device on its ankle while in a feedlot and grazing in a pasture. Over the course of a day, the researchers expected that their device could harvest almost 30 Joules from a cow in a feedlot, and over 100 Joules from one roaming a pasture. This power could be stored in a battery and used to power monitoring technology, like GPS, pulse, and temperature sensors.