4D printer

4D printing uses the same techniques of 3D printing through computer-programmed deposition of material in successive layers to create a three-dimensional object. However, in 4D printing, the resulting 3D shape is able to morph into different forms in response to environmental stimulus, with the 4th dimension being the time-dependent shape change after the printing. It is therefore a type of programmable matter where the printed product reacts with parameters within the environment (humidity, temperature, voltage, etc.) and changes its form accordingly.

Biomedical
A 4D-printable, photo-curable liquid resin made of a renewable soybean-oil epoxidized acrylate is used for human bone marrow stem cell growth. This material's strong qualities of shape memory effect and biocompatibility lead researchers to believe that it will strongly advance the development of biomedical scaffolds.

Cell Traction Force
CTF is a technique wherein living cells fold and move microstructures into their designed shape. This regulates wound healing, angiogenesis, metastasis, and inflammation.

Electrical and Magnetic Smart Materials
Certain good conducting materials can contract and expand under an electric stimulus. Carbon nanotubes are biocompatible and highly conductive. The combination of carbon nanotubes and magnetically responsive particles has been bioprinted for use in promoting cell growth and adhesion, while still maintaining a strong conductivity.

Commerce and transportation
Future applications of 4D-printed materials as programmable products can be tailored to specific environments and respond to factors such as the temperature, humidity, pressure, and sound of one's body or environment. In shipping applications it will allow products to be packaged flat, have containers that react to forces, and repair themselves after failure.