Plucked strings are an exciting sound generation model for technical and timbral exploration. Mechatronic chordophones take advantage of this model and have been the focus of extensive research and exploration in musical robotics, often used as stand-alone instruments or as part of sound art installations. However, no existing chordophone designs have utilised the expressive potential of plucked strings to their full extent.In this paper, we introduce an expressive mechatronic mono-chord that serves as a prototyping platform for the construction of a polystring chordophone. This new chordophone has been developed to offer enhanced dynamic range, fast picking speeds, fast pitch shifter displacement, and additional expressive techniques compared to existing systems.