Softpaste

Softpaste is a category of viscoelastic paste-like materials used in industry and research. The term is used by several manufacturers to describe soft, deformable formulations based on polymer matrices such as silicone, polyurethane, or acrylic systems. Softpaste formulations are designed to be easily extrudable, thixotropic, and capable of retaining shape under low loads while remaining compliant under deformation.

Key properties include shear-thinning rheology, a low modulus comparable to soft tissues, tunable curing or setting times, and compatibility with embedded fillers or pigments. Many are elastomeric after cure and can be formulated for room-temperature curing or in situ crosslinking. Densities and hardness can be adjusted across a broad range by altering the polymer network and additives.

Manufacture and handling involve mixing components, often in cartridge systems, with thickeners, plasticizers, or fillers to adjust viscosity. They cure by solvent evaporation, moisture, or chemical crosslinking. Storage requires temperature control; some formulations are moisture-sensitive. Safety data depends on the specific chemistry and curing agents used.

Applications include soft robotics actuators and grippers, tactile skins and sensors, medical training phantoms and organ models, 3D-printed soft structures, and protective coatings for delicate components, as well as artistic and design uses.

The term Softpaste is a generic descriptor rather than a single proprietary product. Formulations emerged as developers sought materials that combine softness, durability, and ease of processing, with ongoing research into biocompatible and recyclable variants.