Mechanics of Biological Systems & Micro-and Nanomechanics, Volume 4 of the Proceedings of the 2018 SEM Annual Conference & Exposition on Experimental and Applied Mechanics, the fourth volume of eight from the Conference, brings together contributions to important areas of research and engineering.  The collection presents early findings and case studies on a wide range of topics, including:Cell Mechanics & Traumatic Brain InjuryMicromechanical TestingAdhesion and FractureMEMS Devices and TechnologyNano-scale Deformation Mechanisms1D & 2D MaterialsTribology & WearResearch and Applications in Progress