In your hands it is soft and spreadable and feels like the kind of slime children play with. However, look closer and squeeze this substance and it generates electricity - with a variety of applications that span health care and clean energy production.
The slime, or gel, as Dr. Erica Pensini refers to it is a discovery the environmental engineering professor came upon "serendipitously" while trying to capture amines using surfactants in her research on water contaminants.
"I became curious about the electrical properties of these molecular structures interacting," Pensini explains. "This is how the gel came about."
Collaborating with her colleagues in the College of Engineering and Physical Sciences, including Dr. Aicheng Chen, an electrochemist, Dr. Stefano Gregori, an electrical engineer and Dr. Alejandro Marangoni, an organic chemist in the Department of Food Science, the research was published in the Journal of Molecular Liquids.
"They were important partners in this, with fundamental knowledge that is transferable," Pensini says.
The effect of piezoelectric materials
Researchers experimented with different chemicals and fatty acids; ultimately the gel is comprised of just three materials. The ratio - 90 per cent water and equal parts oleic and amino acids - can be mixed in any order, at any speed, typically at room temperature. It is clear in colour and contains no odours.
The slime, or gel, is clear in colour, odourless and comprised of water and oleic and amino acids.
"The material is completely bio-based," Pensini explains, matching water content in the body that promotes faster healing.
When squeezed or stretched, its gel consistency generates what is known as the piezoelectric effect, generating an electric charge. That ability to change shape makes it ideal for different applications, something researchers discovered using a synchrotron - a particle accelerator - at the Canadian Light Source.
Pensini has experimented using the gel on her own hands to heal skin abrasions from rock climbing. She imagines it installed in flooring, generating clean energy when activated by natural movements such as compression.
There are also possibilities for medical training, drug delivery and wearable technologies; piezoelectric materials can create sensors that monitor health and movement or measure pH levels or lactate content in sweat or even monitor one's gait and contact force.
"The applications are vast and each one of them requires optimization," Pensini says, motivated by the knowledge gap researchers have found in exploring soft electric materials.
"Research is typically built on existing knowledge," she says, "now we're seeing something in a group of materials that was not initially discovered."
