Manipulating mechanical energy in materials creates intriguing new opportunities to enhance performance and enable innovative designs. In this presentation I will discuss two examples of this approach: 1) high capacity, easy release adhesives inspired by the gecko’s toe and 2) soft matter composites for soft robotics. In bio-inspired adhesion, the lack of a fundamental framework that connects biological and synthetic adhesives from basic nanoscopic features to macroscopic systems has resulted in poor performance for synthetic adhesives at large length scales. Starting from basic fracture mechanics, I present and verify a novel scaling theory which leads to an understanding of reversible adhesion in both synthetic and biological systems over 14 orders of magnitude in adhesive force. This simple theory is used to design adhesive pads consisting of stiff, draping fabrics incorporated with thin elastomeric layers which achieve unprecedented force capacities (2950 N over a 100 cm2 area) while maintaining easy release and reusability. For soft robotics, I will discuss an all soft matter composite approach for controlling the electro-elastic and thermo-elastic properties of elastomers through the inclusion of liquid-phase Ga-In metal alloy microdroplets. Experimental and theoretical investigations show that liquid metal droplets incorporated into a silicone elastomer enhance the effective dielectric constant and thermal conductivity while preserving a low elastic modulus (< 250 kPa) and large extensibility (~ 600 % strain). This general approach can be applied to various hyperelastic media to study fundamental electrical and mechanical properties while enabling functionalities such as electronic skins and artificial muscles for a variety of soft robotic systems.
Bio: Michael Bartlett is currently a Postdoctoral Fellow at Carnegie Mellon University working with Professor Carmel Majidi in the Soft Machines Lab. He completed his Ph.D. in Polymer Science and Engineering at the University of Massachusetts Amherst in 2013 under the guidance of Professor Alfred Crosby and his BSE in Materials Science and Engineering at the University of Michigan in 2008. After obtaining his Ph.D. he worked as a Senior Research Engineer in the Corporate Research Laboratory at 3M. His fundamental and applied research has resulted in a number of publications, patents, and awards as well as the invention of GeckskinTM, a new adhesive material which is being commercialized by a startup company and was named one of the top five science breakthroughs of 2012 by CNN Money.