A general fruit acid chelation route for eco-friendly and ambient 3D printing of metals

Abstract

Recent advances in metal additive manufacturing (AM) have provided new opportunities for prompt designs of prototypes and facile personalization of products befitting the fourth industrial revolution. In this regard, its feasibility of becoming a green technology, which is not an inherent aspect of AM, is gaining more interests. A particular interest in adapting and understanding of eco-friendly ingredients can set its important groundworks. Here, we demonstrate a water-based solid-phase binding agent suitable for binder jetting 3D printing of metals. Sodium salts of common fruit acid chelators form stable metal-chelate bridges between metal particles, enabling elaborate 3D printing of metals with improved strengths. Even further reductions in the porosity between the metal particles are possible through post-treatments. A compatibility of this chelation chemistry with variety of metals is also demonstrated. The proposed mechanism for metal 3D printing can open up new avenues for consumer-level personalized 3D printing of metals.

Direct 4D printing of functionally graded hydrogel networks for biodegradable, untethered, and multimorphic soft robots

“…The powder and inkjet cartridges for the 3D printing process setup were prepared in the following manner. First, an aqueous polymer powder was mixed with each functional agent, as described in our previous study [41]. Next, the feeder box and builder box were filled with the polymer powder and functional agent mixture.…”

“…In this sense, a different type of printing methods called Binder Jetting 3D Printing (BJ3DP) has emerged as a promising alternative with distinct advantages [38][39][40]. The BJ3DP can use various materials, such as polymers [9,38], ceramics [39,40], and metals [41,42], and it is a representative technology that can quickly and elaborately create porous 3D structures [43,44]. Porous structures that are created using polymeric materials have a further advantage in realizing intelligent soft robotics because they have a large surface area and can be highly sensitive to stimuli from the external environment (humidity, gas, temperature, etc) [45][46][47][48].…”

Evaporate-casting of curvature gradient graphene superstructures for ultra-high strength structural materials

“…Structural material processing plays crucial roles in virtually all aspects of modern manufacturing and industry, enabling the fabrication of customized, complex, and precision parts that are durable and well-suited for various applications, spanning from electronics to aerospace and automotive industries 1 – 3 . However, current material forming technologies suffer from internal stress or defects arising from the relative displacement of material molecules (or atoms) during the processing, which lead to a noteworthy attenuation of the intrinsic mechanical properties and a deterioration of processing precision 4 – 6 . In line with the development of two-dimensional materials over the past decades, microstructures constructed from graphene and its derivatives as basic building blocks have showcased tremendous potential, demonstrating that the bottom-up self-assembly is an effective strategy to address the processing challenge 7 , 8 .…”