Terminator-Inspired Liquid Metal Lattice Reforms When Heated, Probably Won't Target John Connor
Inspired by the T-1000 from Terminator 2, researchers have created a liquid metal lattice which reforms its shape when melted.
Comparing your creation to the relentless shape-shifting robot star of Terminator 2: Judgement Day is an interesting choice from someone who says he has never actually seen the film, but while Professor Pu Zhang's liquid metal lattice isn't exactly a polymimetic alloy it is a technique for printing objects from with some interesting properties.
Zhang compares the liquid metal objects he and his team create to the T-1000 from Terminator 2, while admitting that "I've never watched that movie" — but the comparison isn't entirely a joke. Zhang's liquid metal lattice, constructed from Simon Quellen Field's bismuth, indium, and tin alloy, showcases how the metal can be used for some interesting 3D-printed objects.
"Without the shell, it won't work, because the liquid metal will flow away," Zhang describes. "The shell skeleton controls the overall shape and integrity, so the liquid metal itself can be confined in the channels. We spent over half a year developing this manufacturing process, because this new lattice material is very hard to process. You need to find the best materials and processing parameters."
The process combines technology from the fields of 3D printing, vacuum casting, and conformal coating to produce prototypes ranging from web-shaped mesh antennas to honeycombs and footballs, all of which can return to their original shapes after being heated to melting point - and, just in case the comparison wasn't clear, there's a hand reforming itself thrown in for good measure.
The resulting visuals are impressive, but Zhang and team claim that there are practical applications too: The metal is strong when in sold form, and can absorb considerable energy when crushed; it can then be heated to melting point to return it to its original shape for re-use without the need for re-casting.
"A spacecraft may crash if it lands on the moon or Mars with some kind of impact. Normally, engineers use aluminium or steel to produce the cushion structures, but after you land on the moon, the metal absorbs the energy and deforms. It's over — you can use it only once," Zhang explains. "Using this Field's alloy, you can crash into it like other metals, but then heat it up later to recover its shape. You can use it over and over again."
The team's work has been published in the journal Additive Manufacturing under closed-access terms.
