Multifunctional atomic force microscope cantilevers with Lorentz force actuation and self-heating capability

作者：Somnath Suhas^*; Liu Joseph O; Bakir Mete; Prater Craig B; King William P

来源：Nanotechnology, 2014, 25(39): 395501.

DOI：10.1088/0957-4484/25/39/395501

• atomic force microscope (AFM)
• Lorentz force
• heated cantilever
• thermal topography imaging
• magnetic actuation
• tapping-mode AFM

This paper reports the development of microcantilevers capable of self-heating and Lorentz-force actuation, and demonstrates applications to thermal topography imaging. Electrical current passing through a U-shaped cantilever in the presence of a magnetic field induces a Lorentz force on the cantilever free end, resulting in cantilever actuation. This same current flowing through a resistive heater induces a controllable temperature increase. We present cantilevers designed for large actuation forces for a given cantilever temperature increase. We analyze the designs of two new cantilevers, along with a legacy cantilever design. The cantilevers are designed to have a spring constant of about 1.5 N m(-1), a resonant frequency near 100 kHz, and self-heating capability with temperature controllable over the range 25-600 degrees C. Compared to previous reports on self-heating cantilevers, the Lorentz-thermal cantilevers generate up to seven times as much Lorentz force and two times as much oscillation amplitude. When used for thermal topography imaging, the Lorentz-thermal cantilevers can measure topography with a vertical resolution of 0.2 nm.

• 出版日期2014-10-3