An automated device for manufacturing microneedles of iterated shape

摘要

A computer-controlled device allows for obtaining metallic microneedles with a vertex radius of ～10 nm from wire bars by using the electropolishing technique. The microneedles have a highly reproducible shape and a nondisturbed interior microstructure of bars. The essence of the method consists in terminating the process at an optimal instant determined from the time dependence of the electric current by using a computer program. The microneedles obtained are utilized as point electron sources, samples in field-emission microscopy, and indenters in tunneling microscopy.