Highly deformable, soft elastic, viscoelastic and poro-elastic materials occur in many different fields of research, e.g. adhesives,therapeutic patches, shock absorbers, dampeners, platforms for micro-fluidic devices, biomaterials, prosthetic devices, in biology as soft tissues, stems, roots and leaves, sponges, cartilage layers and in cutting-edge research fields like soft robotics, wearable electronics, conforming interfaces for biological surfaces and so on. In these variety of applications these materials are subjected to many different forms of mechanical loads, e.g. tension, compression, torsion, bending; apart from surface traction, these materials are subjected to also different body forces, e.g. electric and magnetic field. Due to the large deformability, their specific geometrical features and complex rheological character, these materials respond differently from that commonly observed with linear elastic materials. In our laboratory, we study these materials in the context of adhesion, friction, fracture and failure. Our works have led to the development of several technologies: a soft, bi-convex, aspherical optical lens for microscopy applications, a reusable paper for writing, drawing and printing over repeated applications, a washable sticky surface and a precipitant-less method for crystallization of protein molecules.