The most interesting materials I found at MaterialConnexion was this soft gel aptly named “Softgel” made by TechnoGel Italia (there is a PA based distributor or subsidiary company which can be contacted through their website). This product was displayed as a colored block of around 8” x 8” x 2” with bumps on one side. It was extremely soft (low shore hardness) and pliable to the touch, feeling as though there were a liquid gel bound inside a relatively harder exterior shell. When pressed and released, however, the material slowly returned to its original shape, indicating that it is in fact a solid.
Most interesting about this material was that it tricked me! Unlike most materials which fall squarely within one or another form (solid vs liquid / pliable vs rigid / etc.) this material exhibited properties not commonly found together. Specifically, it felt like a liquid and acted like a solid. This set of uncommonly mixed properties is not by chance, but baked into the product’s design. According to the company:
Minimal bonding between the chains of molecules creates a highly fluid rheology similar to a liquid, while retaining the shape retention properties of a solid. The material is highly deformable, distributing applied pressure across the surface, before returning to its original shape upon the removal of force. The softness of the gel is achieved through the low degree of molecular cross-linkage, the amount of bonding determines the suppleness of the gel.
This company’s intention is not, however, to delight passers-by through subversive of their long-held tactile assumptions. There are a number of specific industry use-cases for a material with these particular properties, and there is a clear advantage (according to the company) of this product over the state-of-the-art:
By utilizing the molecular structure to control the gel’s rheology; increasing or decreasing the shore hardness does not require the addition of plasticizers or other additives. This ensures that the physical properties will not alter over time as is common with other plasticized (softened) polymers, which occurs when the plasticizing additives migrate or evaporate out of the system.
And the listed use-cases are far from surprising:
Applications include shoe insoles, athletic gear, medical technologies, furniture, toys, sealing, gaskets, bedding, ergonomic contouring, handles and grips.
This material managed, with very little by way of presentation, to excite and delight me simply through its unusual physical properties. It helped clarify for me something that I thought I knew: that there is a great deal of opportunity in surprise. This concept is used to great effect in physical comedy and in narrative arcs, and it is inspiring to know that it remains true in other fields. While I don’t have a specific use-case for this gel in my soft robotic explorations, I am appreciative of this small reminder that surprise can be an effective tool in many fields.