A team of researchers hailing from multiple Australian universities has achieved a remarkable feat—creating a piezoresistor of astonishing miniaturization, measuring a mere 500,000 times smaller than a human hair. This exceptionally sensitive electronic component has the ability to convert force into electrical signals, holding immense promise for groundbreaking applications in biosensors and health monitoring.

Piezoresistors are commonly employed for detecting vibrations in various electronic devices and automobiles, such as in smartphones for step counting and in cars for airbag deployment. They are also integral to medical devices like implantable pressure sensors, as well as in aviation and space travel.

A Game-Changing Advancement in Piezoresistor Technology

This significant breakthrough in piezoresistor technology is the result of a nationwide research initiative led by Dr. Nadim Darwish from Curtin University, Professor Jeffrey Reimers from the University of Technology Sydney, Associate Professor Daniel Kosov from James Cook University, and Dr. Thomas Fallon from the University of Newcastle. The team has crafted a piezoresistor that is astonishingly minute, measuring approximately 500,000 times smaller than the width of a human hair. According to Dr. Darwish, they have succeeded in developing a more sensitive, miniaturized version of this critical electronic component, which converts force or pressure into electrical signals and finds applications in numerous everyday scenarios.

Promising Applications and Features

Dr. Darwish underscores the transformative potential of this new piezoresistor: “Because of its size and chemical nature, this new type of piezoresistor will open up a whole new realm of opportunities for chemical and biosensors, human-machine interfaces, and health monitoring devices. As they are molecular-based, our new sensors can be used to detect other chemicals or biomolecules like proteins and enzymes, which could be game-changing for detecting diseases.”

Scientific Foundation for the Breakthrough

Dr. Fallon explains that the new piezoresistor is constructed from a single bullvalene molecule, which reacts to mechanical strain, resulting in the formation of a new molecule with a different shape. This transformation leads to changes in electricity flow by altering resistance. These distinct chemical forms, known as isomers, have been harnessed for the development of piezoresistors for the first time. The researchers have been able to model the intricate series of reactions taking place, offering insights into how individual molecules can react and transform in real-time.

Implications for Molecular Electronics

Professor Reimers underscores the significance of this development, noting that it enables the electrical detection of shape changes in reacting molecules at a remarkable rate of about once every millisecond. Detecting molecular shapes through their electrical conductance represents a pioneering concept in chemical sensing. Meanwhile, Associate Professor Kosov highlights the critical role of this understanding in determining the fundamental properties of connections between molecules and attached metallic conductors in all future molecular electronics devices.

In essence, this miniature piezoresistor achievement opens the door to a new era of biosensors and health monitoring, with the potential to revolutionize disease detection and usher in a future where molecular electronics devices play an increasingly central role.

By Impact Lab