Heated nano cantilever tip can make electronic measurements

Nano-sized cantilever tips with integrated heaters are widely used to characterise polymer films in electronics and optical devices, pharmaceuticals, paints, and coatings. They are also used in research labs to explore ideas in nanolithography and data storage, and to study the fundamentals of nanometre-scale heat flow.

Until now, however, the researchers claim no one has used a nano-tip for electronic measurements.

‘We have developed a new kind of electro-thermal nanoprobe,’ said Prof William King, from the Department of Mechanical Science and Engineering at Illinois. ‘Our electro-thermal nanoprobe can independently control voltage and temperature at a nanometre-scale point contact. It can also measure the temperature-dependent voltage at a nanometre-scale point contact.’

‘Our goal is to perform electro-thermal measurements at the nanometre scale,’ said Patrick Fletcher, first author of a paper describing the work that was published in the journal Nanotechnology. ‘Our electro-thermal nanoprobe can be used to measure the nanometre-scale properties of materials such as semiconductors, thermoelectrics, and ferroelectrics.’

The electro-thermal probes are different to the thermal nanoprobes typically used in King’s group and elsewhere because they have three electrical paths to the cantilever tip.

Two of the paths carry heating current, while the third allows the nanometre-scale electrical measurement. The two electrical paths are separated by a diode junction fabricated into the tip. While the cantilever design is complex, the probes can be used in any atomic force microscope.

The research was sponsored by the Office of Naval Research and the Air Force Office of Scientific Research.