For the last category of energy dissipation we chose the overarching term of self-assembly. The respective systems are often driven by a combination of multiple short-range interactions and therefore, cause complex self-assembly processes, such as in helix formation, protein folding or the binding of guest to host molecules. Helix conformations are common structural elements of biopolymers (e.g., DNA α-helix). Similarly, certain natural polymers, such as gelatin, gellan gum, and agarose, form helical structures that are stabilized by hydrogen bonding and/or ionic interactions (Figure ). Gelatin is a degradation product of collagen, while agarose is a polysaccharide extracted from certain seaweed. Both are soluble in water and enter a helix-to-coil transition above temperatures of 40 °C. Upon cooling biopolymer solutions, gelation occurs due to the reformation of double helices resulting in thermoreversible networks. Many naturally occurring biological materials contain folded globular proteins, which can undergo reversible forceinduced unfolding, leading to large extension of the polypeptide chain and effective energy dissipation. In the case of the giant muscle protein titin, reversible unfolding helps to prevent damage to muscle tissue, for instance, due to overstretching. Similarly, elastin-like proteins (ELP) mimic the rubber-like stretchability of elastin, one of the most abundant proteins in the human body. Both cases have inspired the development of tough hydrogels through protein folding alike (Figure ). Host-guest inclusion complexation occurs when a guest molecule penetrates the interior cavity of a larger, hollow host molecule, with the earliest investigated host molecules being crown ethers and cyclodextrins (CD). The latter are cyclic oligosaccharides with either 6 (α-CD), 7 (β -CD), or 8 (γ-CD) glucose repeating units. Beside CDs, other macrocycles such as cucurbit[n]urils (CB[n]) or pillar[n]arenes have gained increasing interest in the material sciences. CB[n] macrocycles consist of glycoluril units and have much more rigid cavities as compared to CDs, their portals being laced with carbonyl groups that enable strong binding with cationic guests. Compared to CDs, CB[n] host-guest interactions cover a broad range of binding affinities reaching values up to K a = 10 17 M -1 . Consequently, they have been used in a variety of supramolecular hydrogels and although stiff and stretchable hydrogels were obtained, their fracture mechanical properties largely remained unknown. Rather than classical hostguest inclusion complexation involving guest-and/or hostfunctionalized polymers, the two discussed examples of tough hydrogels herein used CD host-guest self-assembly to enable a unique network topology known as slide-ring gels (Figure ). In this scenario, CDs are threaded onto long polymer chains prior being cross-linked to form a network with slidable cross-links. The consequences of slidable cross-links onto the material properties are fascinating and have created both a new subfield in the area as well as a powerful energy dissipation mechanism for tough hydrogels.