System overview and sensor for a bone plate model. (A) System overview of sensor embedded in a mouse femur fracture, where the injury is stabilized with a bone plate. Image created by the Ella Maru Studio. (B) Sensors fabricated on a polyimide substrate with 700 µm2 platinum (Pt) electrodes spaced 0.5 mm apart. Sensors were affixed to the proximal half of the bone plate, with a long flexible cable extending off the proximal end. The serpentine pattern repeated for the length of the cable, ending in two vias that served as connectors that link to the measurement hardware. (C) Photograph of open surgery performed to implant a bone plate and affixed sensor to stabilize a femur fracture. Surgical site was closed following sensor placement. (D) Fluoroscopy image of implanted Pt sensor in the fracture gap.