Applications of Bioinspired Reversible Dry and Wet Adhesives: A Review

<jats:p>Bioinspired adhesives that emulate the unique dry and wet adhesion mechanisms of living systems have been actively explored over the past two decades. Synthetic bioinspired adhesives that have recently been developed exhibit versatile smart adhesion capabilities, including controllable adhesion strength, active adhesion control, no residue remaining on the surface, and robust and reversible adhesion to diverse dry and wet surfaces. Owing to these advantages, bioinspired adhesives have been applied to various engineering domains. This review summarizes recent efforts that have been undertaken in the application of synthetic dry and wet adhesives, mainly focusing on grippers, robots, and wearable sensors. Moreover, future directions and challenges toward the next generation of bioinspired adhesives for advanced industrial applications are described.</jats:p&gt

Highly stretchable and tough magnetic-responsive composites with a wide range of modulus tunability for multifunctional soft robots

Department of Mechanical EngineeringWe propose two types of multifunctional soft bodies with highly stretchable and tough dual-responsive materials capable of achieving a wide range of variable stiffness values. The primary focus of this dissertation is the wide stiffness variation and rapid thermo-/magneto-responsiveness of highly resilient magnetic composites. Because the proposed highly stretchable and resilient magneto-responsive material allows for large conformational changes when subjected to heat stimuli based on a one-way shape memory effect, it exhibits an excellent shape recovery effect and generates high-power contractile strength.clos

Cellulose acetate nanoneedle array covered with phosphorylcholine moiety as a biocompatible and sustainable antifouling material

Extensive efforts have been devoted toward developing antibiofilm materials that can efficiently suppress bacterial attachment and subsequent biofilm formation. However, many of the previous approaches are based on non-biocompatible, non-degradable, and environmentally harmful synthetic materials. Herein, we report an efficient and sustainable biofilm-resistant material that is made of a biocompatible, biodegradable, and naturally abundant cellulose derivate biopolymer. The biofilm-resistant material is made of cellulose acetate (CA) and possesses precisely defined nanoscale needle-like architectures on its surface. The CA nanoneedle array is further coated with a cell-membrane mimicking monomer of 2-methacryloryloxyethyl phosphorylcholine (MPC). Based on the synergetic integration of the bio- and environment-friendly polymers of CA and MPC into nanoscale topography, the nanostructured CA not only effectively prevents bacterial attachment but also simultaneously exhibits strong bactericidal effects against both gram-positive and gram-negative bacteria. This natural cellulose derivative-based nanostructured material has strong potential as a biocompatible, and eco-friendly antibiofilm material for versatile uses in biomedical and industrial applications

Flexible and shape-reconfigurable hydrogel interlocking adhesive for high adhesion in wet environments

We present wet-responsive, shape-reconfigurable and flexible adhesives that exert strong adhesion under wet environments based on a reversible interlocking between reconfigurable hydrogel microhook arrays. Based on the hydration-triggered shape reconfiguration of the hydrogel microstructures, the adhesions between interlocked microhook arrays were greatly elaborated under wet conditions. Furthermore, the wet adhesion was monotonically increased with water-exposure time. The maximum adhesion force as high as ~79.9 N cm-2 in the shear direction was obtained with the hydrogel microhook array after 20 h swelling. A biomedical bandage utilizing the hydrogel microhooks was proposed as an example of the possible applications