Reduced Dimensions Autonomous AFM System for working in Microbiorobotics

In this paper we present the design of the test-bench developed for testing a Scanning Probe Microscopy System placed in an autonomous platform of reduced size (cm3) based on self-sensing probes, which has been designed for working on micro-robotics or other applications where optical detection is not possible or convenient. The micro-robot will hold the SPM scanner at the end of an actuator arm. The tool consists on a 3DOF piezoelectric actuator which allows the robot to scan an XYZ area and a self-sensing probe cantilever assembled at its end instead of the classical optical detection method; it reduces the total dimensions and power requirements. The design is developed as a software/hardware system and we present the hardware circuitry, composed by full custom integrated drivers, the SPM head (sensor and actuator) and the measurement instrumentation. The SPM technique that is implemented is the Atomic Force or AFM microscopy, with a piezo-resistance probe-cantilever to sense the force in the nN range. All the control is done by software by a PC interface, which gives us the chance to do different tests. We present the measurement results on nano-indentation experiments carried out by this tool