Final answer:
A polymer gel is the material described as soft, flexible, and porous, with the ability to absorb water. It is a topic investigated within the field of soft matter physics, particularly in the context of biological systems and innovative engineering applications.
Step-by-step explanation:
The material that is described as soft, flexible, porous and can absorb water is likely a polymer gel, which is a common example of soft condensed matter. Soft matter physics, which has been applied to understand the properties of living systems, studies materials like these where the interactions are weak and can be greatly affected by thermal fluctuations. Cork is another example of a natural, porous material that is both light and can absorb water.
Polymer gels or polymerized capsules, in particular, are known for their ability to swell and desorb water, explaining their softness and flexibility. These properties make them useful in many applications, including biomedicine and engineering. The examples include developments in porous, sponge-like materials that react to light (photoactive materials) and can have diverse applications such as gas diffusion control in hydrogen fuel cells or electronics components.