This scanning electron micrograph shows a nanomechanical torsion oscillator used by computer engineers to measure extremely small amounts of torque.
A nanomechanical torsion oscillator is used to measure extremely small torsion or twisting forces smaller than those created by the untwisting of a strand of DNA. When current passes from magnetic into non-magnetic materials, the directional spins of the electrons flip at the boundary, producing a mechanical torque. This device can measure the torque in a metallic nanowire with unprecedented sensitivity. This approach to measuring torque has applications in spintronics as well as in fundamental physics, chemistry, and biology, and is particularly important in the hard disc industry.
• SIZE: The nanowire at the center of this image has a diameter of about 80 nm.
• IMAGING TOOL: Scanning electron microscope