­Background When a soft tube is pinched, its stiffness is lowered at the pinching location, making it possible to buckle the tube at the pinch location. This phenomenon can be stimulated through the use of mechanical interference and vacuum, tendon-based pulling forces, or by pushing out a hinge from the inside. Once pinched, a hinge is formed...

­Background Tape springs (or tape measures) exhibit nonlinear stiffness and asymmetric behavior when bent in one direction compared to the opposite direction. This behavior can be utilized, tuned and actively reconfigured to achieve locomotion on land and in fluids. Even in the presence of symmetric flapping, a swimming gait similar to “breaststroke”...

Background Unchecked growth of algae and unwanted plants in bodies of water can result in undesirable changes that affect ecological stability, recreational value, and human health. Surface overgrowth of aquatic plants and algae restrict swimming, fishing, and boating, while depleting oxygen available for fish and other plant life. Excess levels of...