Microparticle manipulation on the surface of a piezoceramic actuator

In this paper, a technique called piezoelectric interfacial particle manipulator (PIPM) for the manipulation of single and multiple microparticles on the surface of a piezoelectric actuator is demonstrated. The PIPM is capable of controlled manipulation of single and multiple microparticles ranging in size from 0.5 to 50 µm. Piezoelectrically excited bulk modes of vibration, ranging from 10 kHz to 2 MHz, are used to generate a complex distribution of manipulation forces acting in opposition to particle–surface normal adhesion and tangential frictional forces. The vibration of the PIPM is characterized using a finite element method (FEM) simulation and a theoretical study of the particle–surface interfacial forces. A comparative study of the manipulation forces and the adhesive particle–surface interfacial forces, measured using atomic force microscopy, is performed. The results confirm the ability of the PIPM to overcome adhesion forces ranging from 10 to 250 nN for particles ranging in radii from 10 to 30 µm. Furthermore, reproducible high throughput particle manipulation is demonstrated via the translation of a 25 µm stainless steel particle, over a distance 600 times its radius, with an average speed of 5 mm s−1. Experimental results correlated with theoretical expectations indicate that the PIPM can prove to be a versatile tool for the controlled non-destructive manipulation of single as well as multiple microparticles in the fields of biosensors, tissue engineering, biochips, micro-fabrication and MEMS devices.