wethair

Wethair is a fictional term used in speculative fiction and some tabletop role-playing game settings to describe a moisture-responsive, hair-like material. In most depictions it combines synthetic polymers with bio-inspired keratinous elements to mimic the texture and appearance of human hair while offering programmable mechanical behavior.

Under dry conditions wethair behaves as a stiff fiber with a straight or slightly wavy profile. When exposed to water or high humidity, its polymer network absorbs moisture, causing the material to swell, soften, and become highly flexible. Some variants are designed to respond to temperature or light, enabling shape programming that can be locked in when dry and relaxed when dampened. The material is typically described as lightweight, elastic, and capable of holding complex forms for short periods.

Production and origin of wethair are fictional. It appears in worldbuilding by science fiction authors and game designers rather than as a real material. In many stories, wethair is grown in bioreactors or woven from synthetic keratin fibers reinforced with hydrogel components. Some portrayals include self-healing properties or reversible programming, allowing wearers or operators to alter the hair’s shape, texture, or volume on demand.

Applications within narratives include fashion accessories, disguise, prosthetics, and adaptive cosplay, as well as plot devices about identity and transformation. The term has also entered fan communities as a convenient shorthand for moisture-responsive, dynamic hair effects, though it remains outside real-world science.

See also: hydrogel, smart materials, morphing materials.