3D-printed flowers demonstrate the properties of multi-functional printing gels that react to moisture. Credit: Dartmouth's Ke Functional Research Group.According to a Dartmouth study, 3D-printable gels can be made by using heat to alter the molecular arrangement on a chemical chain. This process has a wide range of functional properties.Researchers call the new process "kinetic trapping". The new process is called "kinetic trapping" by the researchers. The rings can store kinetic energy, just like a spring that is compressed.Researchers from the Ke Functional Materials Group use heat and moisture to alter the distribution of rings.Printing objects with different mechanical strengths with one ink could eliminate the need for multiple inks and save time.Chenfeng Ke is an assistant professor in chemistry and senior researcher. "This new method uses heating to produce and control 3Dinks with a variety of properties," said Chenfeng Ke. It could simplify the 3D printing process for complex objects and make it more affordable.The majority of 3D printing inks have uniform molecular structures that produce printed objects with one property. This could be a desired stiffness or elasticity. It is difficult to print multiple properties on an object. This is because it requires preparing several inks that have been engineered to work together.Researchers created an ink by introducing a molecular speed bump. This changes the distribution of molecular ring over time. These uneven rings transform the material from a powder to a 3D printing gel.Qianming Lin, a Dartmouth graduate student researcher and the first author of this study, stated that "this method allowed us to use heat to create complex shapes and make these acuate at various moisture levels."The video shows how a 3D-printed flower is printed. When exposed to moisture, the flower closes. The arrangement of molecular rings gives different parts of the printed flower flexibility. Combining properties allows soft petals to close, while firmer flowers provide structure.The current 3D printing techniques make it difficult to print the same flower with different materials.Ke stated that the printing ink used to create each part of the object is the same. They have the same chemical composition, but they have different molecular rings and distributions. These differences result in products with drastically different mechanical strengths, and they react to moisture differently.Chem published the study that examines energy-holding states of molecular structures of polyethylene glycol and cyclodextrinsubstances frequently used as food additives or stool softeners. The speed bumps are attached to the polyethylene glycol to make the 3D-printed objects respond to moisture and change their shape.The research team believes that future refinements to the molecule will enable precision control of multiple metastable states. This will allow for the printing "fast-responsive actuators" as well as soft robots with sustainable energy sources like variation in humidity.These printed objects can be used in medical devices and industrial processes.Learn more Smart ink gives 3-D printing new dimensionQianming Lin and colleagues, Kinetic trapping 3D-printable poly(pseudo-rotaxane) networks, Chem (2021). Information from the Journal: Chem Qianming Lin and colleagues, Kinetic trapping 3D-printable poly(pseudo-rotaxane) networks, (2021). DOI: 10.1016/j.chempr.2021.06.004
