This paper discusses a recent three-dimensional assembly process called the Plastic Deformation Magnetic Assembly (PDMA) method. The PDMA method allows three dimensional micromechanical structures to be realized efficiently using surface micromachining and wafer-scale, post-sacrificial-release assembly. We will discuss the principle of the PDMA method, along with the design methodology. The PDMA process has been used for a number of applications, including vertical micro RF inductors, micromachined hot wire anemometers, artificial lateral line sensors, and two dimensional neuron probes. The process for these applications will be discussed to illustrate the usefulness of the PDMA process.