Programmable soft materials containing ferromagnetic domains and methods of making
A responsive material having an elastomeric matrix in which ferromagnetic particles are dispersed so as to have a predetermined magnetization pattern which, when exposed to an external magnetic field, changes the shape of the responsive material from an initial shape to a predetermined transformed shape dictated by the magnetization pattern. An initial shape of the responsive material is formed by direct ink printing while applying magnetic fields to a dispensing nozzle to align the particles and gives rise to the desired magnetization pattern.
1. A transformable material comprising:
an elastomeric material;
ferromagnetic particles dispersed within the elastomeric material to provide an elastomeric-ferromagnetic composite material;
the elastomeric-ferromagnetic composite material having an initial shape; and
the ferromagnetic particles being provided within the initial shape in a predetermined magnetization pattern;
wherein the transformable material changes shape from the initial shape into a predetermined transformed shape different than the initial shape upon application of a magnetic field, and
wherein the predetermined transformed shape depends upon the predetermined magnetization pattern.
2. The transformable material of claim 1 , wherein the elastomeric-ferromagnetic composite material is a printable ink.
3. The transformable material of claim 1 , wherein the elastomeric-ferromagnetic composite material is an elastomeric matrix material including a ferromagnetic material and one or more of a filler, a catalyst, and a crosslinker.
4. The transformable material of claim 1 , wherein the elastomeric material includes Silicone (Polydimethylsiloxane) rubber, Polyurethane (PU) rubber, Styrene Ethylene Butylene Styrene (SEBS) rubber, Polyacrylate rubber, and Polycaprolactone (PCL).
5. The transformable material of claim 1 , wherein the elastomeric material has a glass transition temperature lower than an operating temperature.
6. The transformable material of claim 1 , wherein the elastomeric material has a Young's modulus below 10 MPa.
7. The transformable material of claim 1 , wherein the elastomeric material is a hydrogel.
8. The transformable material of claim 7 , wherein the hydrogel includes one or more of alginate, pectin, and polyvinyl alcohol (PVA).
9. The transformable material of claim 1 , wherein the ferromagnetic particles include an epoxy coating.
10. The transformable material of claim 1 , wherein the ferromagnetic particles are corrosion-resistant.
11. The transformable material of claim 1 , wherein the ferromagnetic particles include iron, cobalt, nickel, an alloy of one or more of iron, cobalt, and nickel, Neodymium-Iron-Boron (NdFeB), Samarium-Cobalt (SmCo), Aluminum-Nickel-Cobalt (AlNiCo), Barium-Iron Oxide (BaFeO), and Iron Oxide (FeO).
12. The transformable material of claim 1 , wherein the elastomeric material includes a rheological modifier, the rheological modifier being one or more of fumed silica nanoparticles, graphene, nanoclay, and cellulose nanofibrils.