We have developed a process for multistep sequential batch self assembly of complex three dimensional ferromagnetic microstructures. The process uses the magnetic torque generated by an external magnetic field perpendicular to the substrate to lift hinged structures. In our previous study, we found that a nondimensional factor that depends on its shape determines the sensitivity of the micro hinged structures to a magnetic field. This factor can be used as a criterion in designing a process for sequential batch self assembly, because the factor indicates the differences in the sensitivity. In this study, we designed multistep sequential assembly by using the nondimensional factor. Four step sequential batch assembly was demonstrated using this method.
In this paper we present a novel method for batch assembly of polysilicon hinged structures. The method uses ultrasonic vibrations generated with an attached piezoelectric actuator to vibrate polysilicon plates on silicon nitride or polysilicon surfaces. We believe that the rubbing between the substrate and the structures creates contact electrification charge that results in hinged flaps to be stabilized vertically on the substrate at elevated temperatures. Furthermore, the ultrasonic triboelectricity is shown to be the most likely explanation due to the observed "memory effect" in which assembly occurs even without further ultrasonic actuation after the initial ultrasonic assembly. This method has been used to batch assemble an array of hinged flaps, retroreflectors, and plates with retaining springs.
We consider the one-dimensional symmetric simple exclusion process with nearest neighbor jumps and we prove estimates on the decay of the correlation functions at long times.