5149

Iowa State University researchers have developed a method of using undercooled metal particles for adhesives to irregular surfaces, including to bio-based surfaces. Certain surfaces are difficult to adhere metal to. This technology allows the creation of heat-free mechanical-bonding driven, reversible printing of metallic conductive traces on complex soft or textured substrate via three different methods (mechanical brushing, spray deposition, and spin coating). 

ISURF 5149 is still in the early stages, it will need considerable funding to scale.

ISURF 5149 uses the SLICE (Shearing Liquids Into Complex paticlEs) method as described by previous disclosures to create the metal droplets necessary for this technology. A wider polydispersity of particles are required to allow the filling of surface irregularities and to produce a denser product. Particles can be applied to surfaces in different ways such as mechanical brushing, spray deposition, or spin coating. Once applied, particles are sintered via a chemical sintering process. This technology allows for the adhesion of metals onto numerous types of surfaces including those considered difficult or impossible such as certain biological substrates. This easy adhesion can be useful for applications such as low-heat welding, bio-metal molding, or creation of delicate circuitry. 
The method of application is a critical component to this technology and along with the need for polydisperse particles separates this from other SLICE technologies. 

• No loss of strength in certain alloys

• Allows adhesion of metals to irregular surfaces

• Increased accuracy in the production of delicate circuitry

• Metal inks become much easier to use on metal surfaces

Printing of conductive traces are a wide-range of surfaces for uses such as sensors or flexible electronics 

A. Martin, C. Du, A. Pauls, T. Ward, M. Thuo “Polydiversity-Driven Printing of Conformal Solid Metal Traces on Non-Adhering Biological Surfaces” Adv. Mat. Int. 2020, 7, 2001294

J. J. Chang,§ A. Martin,§ C. Du, A. Pauls, M. Thuo “Heat-Free Biomimetic Metal Molding on Soft Substrates” Angew. Chem. 2020 59, 16346-16351

Patent(s) applied for