Fever is a physiologic disorder in which the body’s temperature rises above normal. Any condition in which exogenous or endogenous heat gain exceeds heat dissipation mechanisms, such as vigorous exercise, exposure to a warm ambient temperature, or the use of drugs that cause excess heat production or limit heat dissipation, can result in an elevated body temperature. The chemicals produced by the immune system, which reset the body’s thermostat to a higher level, cause the fever caused by a viral or bacterial infection. Most cases of mild fever resolve on their own within a few days.
Researchers hope to use the thermal energy produced by body heat to power a small electronic device capable of detecting fever in the wearer. During the COVID-19 pandemic, public temperature checks have become common practice around the world, and researchers at Texas A&M University are working to make it possible to conduct the test on a large group of people faster and less expensively than current methods.
Our device is based on carbon steel corrosion to generate voltage and current. The lifetime of our device depends on the speed of the corrosion process.Dr. Choongho Yu
Dr. Choongho Yu, professor and Sallie and Don Davis ’61 Faculty Fellow II in the Department of Mechanical Engineering is collaborating with his students to harness the thermal energy generated by body heat to power a small, self-sustaining electronic device capable of detecting fever in its wearer. The team’s findings were recently published in the journal Nature Communications.
If successful, Yu believes such a device could benefit a large number of people, particularly when used in a public setting, by detecting fever quickly and efficiently. “The fever detector can be distributed to many unspecified people at low cost in public places,” Yu said. “This technique could be helpful in the early and rapid detection of fever commonly observed from a viral infection such as COVID, SARS, MERS, and swine flu.”
According to Yufan Zhang, a graduate student who works on the project with Yu, while fever detection can be an effective way to reduce viral transmission during a pandemic, a low-cost, visible, and self-sustaining technique is required to achieve this goal.
“Thermal energy scavenging has a lot of potentials because an output voltage can be obtained by a temperature difference supplied by the fever,” Zhang said. “An electrochromic fever detector has been built and connected to the thermal energy harvester to visualize temperature changes.”
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, using new thermo-hydro-electrochemical energy conversion principles.
“Our device is based on carbon steel corrosion to generate voltage and current,” Yu said. “The lifetime of our device depends on the speed of the corrosion process.”
An electrical charge can be generated by utilizing thermal energy that would otherwise be wasted by the user via the corrosion properties of carbon steel electrodes. An electrochromic fever detector was created and linked to a thermal energy harvester. The thermal-to-energy conversion of the device generates an unprecedented 87 millivolts per degree Celsius. This is a lot more than traditional thermoelectric devices, which require 1000 devices to produce an equivalent voltage.
Given the typical rate of corrosion for carbon steel, Yu estimates that the amount used by their device could last more than a decade. While the team is still working to improve the device’s power and current, the preliminary results are promising, with the observed thermal-to-energy conversion generating an unprecedented 87 millivolts per degree Celsius. This has provided a few volts – sufficient to power typical wearable electronics – by connecting four to eight devices in series, as opposed to conventional thermoelectric devices, which require at least 1000 devices to achieve an equivalent voltage.