There are numerous heat-controlled polymers which change shape when a certain temperature is applied. There is a new material in town, though. It has been developed by a research team lead by professor Mitch Anthamatten at the University of Rochester. It changes shape when the temperature rises to about 35 degrees Celsius – just below body heat level.
The unusually low temperature, as far as the heat-triggered polymers go, makes the material quite outstanding. The number of possible applications seems impressive even at first glance. The developers mention a variety of medical solutions, such as sutures, artificial skin, body-heat assisted medical dispensers etc. However, there is also talk of self-fitting wearables and of certain mechanical operability.
The material is a shape-memory polymer, which can be programmed to retain a temporary shape until it is triggered, by means of heat, to return to its original shape. “Tuning the trigger temperature is only one part of the story. We also engineered these materials to store large amount of elastic energy, enabling them to perform more mechanical work during their shape recovery,” said professor Anthamatten.
The amount of mechanical work performed as the material’s shape transforms back to its permanent state turns out to be surprisingly big. As of now the polymer is said to be capable of lifting an object one-thousand times its weight. Which means that a 100 gram amount of the material should be able to lift one big person, or two smaller ones. Indeed, the research team set out to optimize their polymer to store as much elastic energy as possible.
On the other hand the material can be easily deformed and reshaped and will remain fixed in the form until the required temperature is applied to trigger its return to the initial shape. “Our shape-memory polymer is like a rubber band that can lock itself into a new shape when stretched,” said Anthamatten. “But a simple touch causes it to recoil back to its original shape.”
As far as the practical use of the material is concerned, no industry seems to be more suited for the new solution than 3D printing. Proper personalisation of medical devices and apparel is only achievable by means of 3D printing. Personalised or not, however, with a self-fitting material the notion of one size fits all comes to life with a bang. No more worries of losing or gaining weight!
Obviously, the development requires answers to a couple questions. For example, how a polymer whose formation is triggered by body temperature could be extruded at temperatures beyond boiling? What kind of machines could it be made with? Also, can we really be sure that this beautiful body heat-controlled necklace, with all its stored mechanical power, is not going to strangle our partner? When sensible answers are provided the material is destined to make many 3D printers very, very happy.
Source: University of Rochester