Study of the control process and fabrication of microstructures using a tip-based force control system

The atomic force microscopy tip-based nanomechanical machining method has already been employed to machine different kinds of nanostructures with the control of the normal force of the tip. The previous studies verified the feasibility of the nanomachining approach with the force control. However, there are still some shortcomings of small normal force, small machining scale, high cost and low machining efficiency. Therefore, in this study, a tip-based micromachining system with normal force closed-loop control is established based on the principle of atomic force microscopy. The control parameters are optimized based on an analysis of the control process to enable the production of a constant normal force during machining when using a tip tool. The maximum machining velocity that can be attained using this system while maintaining a constant normal force is obtained based on an analysis of the normal force variations during machining. By controlling nanoscale accuracy and high-precision stage, more complex microstructures, including microsquares, millimeter-scale microchannels and three-dimensional step microchannels, are successfully fabricated using the proposed force control method. Experimental results show that the tip-based normal force control method is a simple, low-cost and versatile micromachining method with the potential ability to machine more complex structures and is likely to find wider applications in the micromachining field.