Which property is crucial for materials used in the development of flexible AM parts?

The correct choice of viscoelasticity is vital for materials used in flexible additive manufacturing (AM) parts due to its unique ability to exhibit both viscous and elastic characteristics when deformed. This property allows the materials to absorb energy and return to their original shape, making them ideal for applications that require flexibility, such as medical devices, soft robotics, and cushioning components.

The viscoelastic nature of these materials enhances their performance by allowing for deformation under stress while also providing the necessary recovery after the load is removed. This characteristic results in improved durability and adaptability in various applications, making viscoelastic materials suitable for products that operate under dynamic loading conditions.

High density is not a desirable trait for flexible materials because a lighter material is often preferred to enhance flexibility and reduce mechanical stress. Tensile strength, while important, does not alone suffice for flexibility; a material may be strong yet rigid, disallowing the desirable bending or stretching characteristics. Brittleness is also problematic since materials that are brittle tend to fracture easily when stressed, which is contrary to the requirements for flexible applications. Therefore, viscoelasticity stands out as the essential property for flexibility in AM parts.