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.