Muschines lack both sentience and autonomy, characteristics which define them from biobots. A biobot can be programmed to perform a task and then left alone while it does it. A muschine, on the other hand, only possesses the responses needed to maintain its own life-functions. A muschine in use requires direct control from an external mind or expert system.
A muschine is a simple device, a muscle-tool really: Something that, when in use, extends the user's reach and power, but which needs guidance to work. A muschine may enhance the user's abilities by a great deal — such as a biological waldo or exoskeleton. Or it may be little more than a living tube of glue or a muscle powered hammer (cf. the Europan Glue Grub and the Arcadian Quillgun) that the user merely picks up, applies the business end to what is being worked on, and squeezes.
Biopower - Text by Anders Sandberg In some worlds a system of living solar collectors for powering underground biospheres is employed - e.g. the Zoeific Biopolity and the Arcadians would build such systems when settling an otherwise inhospitable world. The bases are visible only as verdant green smears of shimmering electromoss, with the tunnels far below the surface.