Micro-machined (e.g., stress-engineered spring) structures are produced by forming a release layer, forming a partially or fully encapsulated beam/spring structure, and then releasing the beam/spring structure by etching the release layer. The encapsulation structure protects the beam/spring during release, so both the release layer and the beam/spring can be formed using plating and/or using the same material. The encapsulation structure can be metal, resist, polymer, oxide, or nitride, and may be removed after the release process, or retained as part of the completed micro-machined structure.