Physics / mechanism
Hydrogels are crosslinked polymer networks swollen with water (typically 70–99 wt%). The network—covalent, ionic, or physically crosslinked—resists dissolution while retaining aqueous fluid via osmotic pressure and enthalpic polymer–water interactions. Key parameters: crosslink density (controls mesh size, ~1–100 nm), elastic modulus (0.1 Pa to ~100 kPa, tunable), swelling ratio, and degradation rate. Stimuli-responsive variants (thermo-, pH-, photo-responsive) switch state via phase transitions, e.g. PNIPAM collapses above LCST ~32 °C. State-of-the-art: nanocomposite hydrogels achieve tensile strains >1000%; conductive hydrogels reach ionic conductivities ~10 mS/cm, relevant to bioelectronics. Bioprinting-grade materials now hit <50 µm feature resolution.
Competitive landscape
Competing material classes include elastomers (silicones, polyurethanes—higher mechanical strength, no hydration requirement), aerogels (ultra-low density, structural but non-aqueous), and cryogels (macroporous, suited for cell scaffolding). In drug delivery, lipid nanoparticles and polymeric micelles compete on encapsulation efficiency. In wearables/bioelectronics, ionic liquids and conducting polymers (PEDOT:PSS) are direct alternatives. Organogels occupy a niche where aqueous instability is prohibitive.
Companies using
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Frontier (open questions)
- To be added.