A team of researchers from Georgia Institute of Technology and two other institutions has developed a new 3-D printing method to create objects that can permanently transform into a range of different shapes in response to heat.
The team created the objects by printing layers of shape memory polymers with each layer designed to respond differently when exposed to heat.
This new approach significantly simplifies and increases the potential of 4-D printing by incorporating the mechanical programming post-processing step directly into the 3-D printing process.
This allows high-resolution 3-D printed components to be designed by computer simulation, 3-D printed, and then directly and rapidly transformed into new permanent configurations by simply heating
Their development of the new 3-D printed objects follows earlier work the team had done using smart shape memory polymers (SMPs), which have the ability to remember one shape and change to another programmed shape when uniform heat is applied, to make objects that could fold themselves along hinges.
To demonstrate the capabilities of the new process, the team fabricated several objects that could bend or expand quickly when immersed in hot water – including a model of a flower whose petals bend like a real daisy responding to sunlight and a lattice-shaped object that could expand by nearly eight times its original size.
The new 4-D objects could enable a range of new product features, such as allowing products that could be stacked flat or rolled for shipping and then expanded once in use. Eventually, the technology could enable components that could respond to stimuli such as temperature, moisture or light in a way that is precisely timed to create space structures, deployable medical devices, robots, toys and range of other structures.
