A computer-readable medium stores a specification for a circuit layout. The compositions may include a biopolymer matrix having positively charged functional groups, negatively charged functional groups, zwitterionic functional groups, or a combination thereof, such that the composition is substantially zwitterionic. The camera and weight are freely rotatable within the housing about an axis such that gravitational forces maintain the rotational orientation of the camera independent of the housing. A mechanism is provided to secure the hub to the shaft so that the shaft extends through the bore. Mounting adapters enable the mounting flanges to mate with corner posts having round holes as well as those having square holes.