Body heat-powered sensor could detect fever in large groups

An employee checks another employees temperature before entering a store on November 27, 2020 in Louisville, Kentucky. (Credit: Jon Cherry/Getty Images)

Researchers hope to make it possible to check the temperatures of large groups of people more quickly and less expensively than current methods allow.

Public temperature checks have become common practice around the world during the COVID-19 pandemic.

The researchers are working to harness the thermal energy generated by body heat to power a small, self-sustaining electronic device capable of detecting fever in its wearer.

If successful, the device could benefit a large number of people—especially when implemented in a public setting—by quickly and efficiently identifying fever.

“The fever detector can be distributed to many unspecified people at public places at a low price, and this technique could be helpful in the early and fast detection of fever commonly observed from a viral infection such as COVID-19, SARS, MERS, and swine flu,” says Choongho Yu, professor and fellow in the mechanical engineering department at Texas A&M University.

Graduate student Yufan Zhang, who works with Yu on the project, says that while fever detection can serve as an effective way to minimize viral transmission during a pandemic, a cheap, visible, and self-sustainable technique is needed to accomplish this goal.

“Thermal energy scavenging shows great potential since an output voltage can be obtained by a temperature difference supplied by the fever,” Zhang says. “To visualize the temperature changes, an electrochromic fever detector has been fabricated and connected to the thermal energy harvester.”

Using new principles of thermo-hydro-electrochemical energy conversion, Yu and his team are working to develop an effective method of providing charge to their fever detection device by harnessing the thermal energy typically wasted by its user via the corrosion properties of carbon steel electrodes.

“Our device is based on carbon steel corrosion to generate voltage and current,” Yu says. “The lifetime of our device depends on the speed of the corrosion process.”

Given the typical rate of corrosion for carbon steel, Yu says the amount utilized by their device could last for more than a decade.

While the team is still working to improve the power and current of the device, the results so far have been promising, with the observed thermal-to-energy conversion generating an unprecedented 87 millivolts per degree Celsius.

This has provided a few volts—large enough to operate typical wearable electronics—by connecting between four to eight devices in a series, unlike conventional thermoelectric devices that require at least 1,000 devices to get an equivalent voltage.

The paper appears in Nature Communications.

Source: Texas A&M University