There is a great need for the continued development of multifunctional, adaptive and biointegrated prosthetic limbs for individuals who have lost limb function due to trauma, disease or congenital disorders.  Although originally designed as relatively static or simply cosmetic, recent generations of prosthetic devices have demonstrated significantly improved function and utility by electronically interfacing with the patient.  However direct electronic communication with the nervous system via implantable devices remains difficult due to the inflammatory response and the loss of functional neurons near the electrodes. Direct interfaces with bone and muscle must be carefully protected from the possibility of infection at the living tissue--engineered device interface.  In addition, the local mechanical and biological conditions at the tissue interfaces must be optimized in order to preserve their capacity for continual biodynamic maintenance and adaptation.

     In order to overcome these limitations it is necessary to consider the design, synthesis, processing and characterization of functionally and structurally-graded materials that can accommodate the dramatic differences in physical properties between engineered devices and living tissue.  Current engineered prosthetic devices are stiff, inert, dry, and are controlled by electronics.  Living tissues are typically soft, biodynamic, wet, and conduct charge ionically.  We will develop materials to function at the interface between these two systems in order to mediate these large variations in mechanical properties, charge transport, and biological activity. 

     Our work will build on ongoing activities in our laboratories that have focused on developing interfaces between prosthetic devices and tissue that are both structurally sound, electronically active, and biologically compatible. We will address the interfaces between tissue and the prosthetic including (1) bone--frame, (2) peripheral nerve--wire, (3) muscle--sensor, and  (4) skin--protective coating.  In each case we discuss the design, construction, evaluation, and analysis of these interfaces.  Our long-term goal is to create a standardized receptacle that can be used to more rapidly and reliably interface an artificial limb to the body.

     Improvements in the quality and immediacy of health care on the battlefield and the availability of protective body armor have significantly increased the survival rate for soldiers.  However many of these individuals have suffered from serious injuries including the loss of hands, arms, or legs.  Improved prosthetic devices will help these individuals significantly increase their quality of life and ability to contribute to society.  This will also help individuals in the general public with similar needs.