Aug 2, 2012
Direct-stamped nanoinks provide flexible sensing architecture
Researchers from Simon Fraser University in Canada have developed an affordable and process-effective manufacturing method that enables direct printing of functional nanoinks for flexible electronic applications. Scanning electron microscopy images and energy-dispersive X-ray spectroscopy analysis revealed residue-free transfer of silver nanoparticles. The team, led by Woo Soo Kim, demonstrated the fabrication technique by making flexible strain-sensing devices for monitoring tyre pressure.
To test the direct-stamping process, the scientists fabricated strain sensors on two different substrates – "hydrophobic and stretchable" silicone rubber (gauge factor as sensitivity: 3.07) and "hydrophilic and brittle" siloxane (gauge factor: 0.39). In each case the pattern of inter-digitated electrodes responded to strain under both tensile and bending stresses. The strain was monitored by measuring the change in capacitance across the device.
The reported technique is said to overcome the restrictions of other direct-metal patterning methods and allows functional electronic inks to be applied to a flexible substrate in an ambient environment without any complex steps – for example, residue removal by plasma-related etching.
A continuous roll-to-roll process is expected to be easily applicable to the direct-stamping procedure to give high-throughput fabrication of flexible electronic devices such as RFIDs, touch pads, solar cells or displays.
Full details can be found in the journal Science and Technology of Advanced Materials.
About the author
Dr Woo Soo Kim is an assistant professor at Simon Fraser University in British Columbia, Canada. He leads the Functional Materials Engineering Lab and is exploring various green-manufacturing approaches with functional nanoink materials for high-performance flexible electronics and sensors.