US-9885736-B2

A control methodology for scanning tunneling microscopy is disclosed. Instead of utilizing Integral-based control systems, the methodology utilizes a dual-control algorithm to direct relative advancement of a STM tip towards a sample. A piezo actuator and stepper motor advances an STM tip towards a sample at a given distance until measuring a current greater than or equal to a desired setpoint current. Readings of the contemporaneous step are analyzed to direct the system to change continue or...