PROJECT SUMMARY Lower limb amputees rely on prosthetic sockets as the interface with their prosthetic legs. The prosthetic sockets only work well if they fit residual limbs of amputees perfectly. Unfitted sockets cause various health issues for lower limb amputees and could significantly limit amputees’ functionality. Currently, prosthetists lack the capability to diagnose socket fit during the socket fitting procedure, which limits their capability to customize the sockets for better fit. The proposed Easy-to-use, iNtelligent, Affordable LinEr (ENABLE) System for Socket Fit Assessment（ENABLE） system will be used as a diagnosis tool for prosthetists. Based on a novel material, which changes color based on loaded pressure, this Enable system will permit prosthetists to evaluate the socket fit by observing the pressure distribution on the residual limb directly. During the proposed project, we will develop the smart liner system and test it through both bench tests and human subject tests. We will also validate that prosthetists will be able to use the smart liner to make appropriate socket fit diagnosis through simulated clinical cases.