QUT researchers discover new material that could revolutionise wearable technology, using a groundbreaking technique that manipulates the spaces between atoms in crystals to create a flexible semiconductor.
In a study published in the journal Nature Communications, the researchers used ‘vacancy engineering’ to enhance the ability of an AgCu (Te, Se, S) semiconductor. This is an alloy made up of silver, copper, tellurium, selenium, and sulphur, used to convert body heat into electricity.
“Thermoelectric materials have drawn widespread attention over the past few decades in light of their unique ability to convert heat into electricity without generating pollution, noise, and requiring moving parts,” said co-author and researcher Nan-Hai Li.
Vacancy engineering is the study and manipulation of empty spaces, or “vacancies,” in a crystal where atoms are missing, to influence the material’s properties.
These include mechanical properties or optimising its electrical conductivity, or thermal properties.
“As a continuous heat source, the human body produces a certain temperature difference with the surroundings, and when we exercise, that generates more heat and a larger temperature difference between the human body and the environment,” said Li.
Li added that precise control of the material’s atomic vacancies improved its ability to convert heat into electricity and enhanced its mechanical properties, allowing it to be shaped for more complex applications.
To demonstrate the practical application potential of the material, the researchers designed several different micro-flexible devices based on the material that could be easily attached to a person’s arm.
“Thermoelectric materials have drawn widespread attention over the past few decades in light of their unique ability to convert heat into electricity without generating pollution, noise, and requiring moving parts,” said Li.
In a separate study, professor Zhi-Gang Chen and researchers from the ARC Research Hub in Zero-emission Power Generation for Carbon Neutrality developed an ultra-thin flexible film that could power next-generation wearable devices using body heat, eliminating the need for batteries.
“Mainstream flexible thermoelectric devices are currently fabricated using inorganic thin-film thermoelectric materials, organic thermoelectric materials deposited on flexible substrates, and hybrid composites of both,” said Chen.
“The key to advancing flexible thermoelectric technology is to examine wide-ranging possibilities.”
