Structurally Transformable and Reconfigurable Hydrogel-Based Mechanical Metamaterials and Their Application in Biomedical Stents.

Mechanical metamaterials exhibit several unusual mechanical properties, such as a negative Poisson's ratio, which impart additional capabilities to materials. Recently, hydrogels have emerged as exceptional candidates for fabricating mechanical metamaterials that offer enhanced functionality and expanded applications due to their unique responsive characteristics. However, the adaptability of these metamaterials remains constrained and underutilized, as they lack integration of the hydrogels' soft and responsive characteristics with the metamaterial design.

Ultra-high Performance Thermochromic Polymers via a Solid-solid Phase Transition Mechanism and Their Applications.

Thermochromic materials are substances that change color in response to temperature variations. Today, sustainability concerns are the main drivers of thermochromic research, with smart, energy-efficient windows being one of the primary applications. While vanadium oxides and leuco dyes are traditionally the main thermochromic materials, hydrogels operating based on change of solvation have risen as some of the most promising materials due to their high optical transparency and good solar modulating abilities.

Sustainable Vat Photopolymerization-Based 3D-Printing through Dynamic Covalent Network Photopolymers.

Vat photopolymerization (VPP) based three-dimensional (3D) printing, including stereolithography (SLA) and digital light projection (DLP), is known for producing intricate, high-precision prototypes with superior mechanical properties. However, the challenge lies in the non-recyclability of covalently crosslinked thermosets used in these printing processes, limiting the sustainable utilization of printed prototypes. This review paper examines the recently explored avenue of VPP 3D-printed dynamic covalent network (DCN) polymers, which enable reversible crosslinks and allow for the reprocessing of printed prototypes, promoting sustainability.

From ToyBox Study to eToyBox: Advancing Childhood Obesity Reduction in Malaysian Kindergartens.

Prevention and treatment of childhood obesity is a global concern, and in Malaysia, it is considered a national public health priority. Determinants of childhood obesity are multifactorial and include factors that directly and indirectly influence energy balance-related behaviours, including energy intake and energy expenditure. Interventions to address childhood obesity that have multiple components at different levels have been shown to be the most influential.

Toughened Hydrogels for 3D Printing of Soft Auxetic Structures.

Materials with negative Poisson's ratio have attracted considerable attention and offered high potential applications as biomedical devices due to their ability to expand in every direction when stretched. Although negative Poisson's ratio has been obtained in various base materials such as metals and polymers, there are very limited works on hydrogels due to their intrinsic brittleness. Herein, we report the use of methacrylated cellulose nanocrystals (CNCMAs) as a macro-cross-linking agent in poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogels for 3D printing of auxetic structures.