Computationally Guided DIW Technology to Enable Robust Printing of Inks with Evolving Rheological Properties

Abstract

Soft multifunctional materials allow for mechanical sensing or actuation as a response to multiple physical stimuli, while providing material stiffness that mimic soft biological tissues (≈1–10 kPa). One of the main bottlenecks in the state of the art relates to the difficulty for manufacturing complex shapes when using inks whose properties significantly change over the printing time. To overcome this issue, the implementation of a hybrid (theoretical‐experimental) framework that allows optimal printability of time‐dependent viscosity inks by using the direct ink writing technology. Although the rheological properties of the ink vary during printing time, a combination of theoretical and experimental methods provides evolving printing conditions that ensure efficient and robust printability over the process. The method removes the need of introducing additives to the ink. To enable this technology, an in‐house printer that provides flexibility to modulate the extrusion pressure over printing time is developed. The method is validated by manufacturing magnetorheological elastomers and conductive soft materials for specific bioengineering and soft electronics applications.

Voids induce wide-range modulation of elasticity for magnetic elastomers II

“…In recent years, 3D printing has been widely used to manufacture magnetic responsive soft materials. 26,27 We believe that precise control of the spatial distribution of voids by 3D printing is a promising technology to precisely control the magnitude and response speed of the MR effect.…”

Particle mobility and macroscopic magnetorheological effects for polyurethane magnetic elastomers

“…10 In addition, 3D printing technology has recently been widely used to manufacture magnetic responsive soft materials. 11,12 The type of matrix and the type of magnetic particles that have been used in MREs, and the magnitude of the MR effect are well summarized in a recent review. 13 There are many reports describing how magnetic particles move and form chain-like structures in a polymer matrix under a magnetic field by overcoming the resistance force from the surrounding matrix.…”

“…10 In addition, 3D printing technology has recently been widely used to manufacture magnetic responsive soft materials. 11,12 The type of matrix and the type of magnetic particles that have been used in MREs, and the magnitude of the MR effect are well summarized in a recent review. 13…”

Additive Manufacturing of Electrically Conductive Multi-Layered Nanocopper in an Air Environment

“…Several different AM techniques are available to manufacture functional parts from metals, polymers, polymer composites, and ceramic materials. According to ASTM standards, there are seven AM techniques, including Binder Jetting, Electrochemical Deposition, Direct Energy Deposition, Material Extrusion, Material Jetting, Powder Bed Fusion, Sheet Lamination and Vat Photopolymerization [1][2][3][4][5][6][7][8][9][10][11]. In recent years, there has been significant interest in the use of AM across many fields due to its advantages over conventional subtractive manufacturing.…”