MIT scientists have become the first to design a monolithic, fully 3D printed, multi-material, magnetic pump.
According to senior research scientist Luis Fernando Velásquez-García, the new miniature pump is compact, valveless, and operates magnetically.
It measures only 1 centimeter in volume and can be fabricated in 75 minutes in a single process using multiple materials that cost less than $3.89 per unit.
Moreover, it can move both liquids and gases using less power and experiences less clogging than standard manufactured pumps of this size.
This makes it suitable for applications such as fuel cells, power generation and heat exchangers used for cooling computer chips.
The pumps – each slightly less than the diameter of a dime – are shaped as small cylinders crowned by a membrane: On top of the membrane is the fluid chamber, with two valveless ports at the top to attach tubes.
As part of their study, the scientists 3D printed the pump in two ways, using Nylon 12 as the structural material in both.
In the first pump, a magnet was press-fitted into the structure of the enclosing piston.
In the second pump, the scientists used Nylon 12 embedded with neodymium magnet (NdFeB) microparticles to create the pump’s magnetic core.
Nylon 12 is an excellent structural material that can easily absorb large amounts of the magnetic particles.
It is sturdy enough to hold still the NdFeB microparticles during the initial magnetization, which makes possible to create strong permanent magnets, notes Velásquez-García:
“In a softer material, the particles would wobble, resulting in no net magnetization of the magnetic composite.”
The pump is driven by an outside rotating magnet which interacts with the internal magnet to move the piston and deform the membrane, propelling the liquid or gas from one port to the other.
The piston is only constrained by the membrane, so it can move in multiple ways at the same time when activated by the external magnet.
And since it is magnetically driven, the new device is more portable than pneumatic pumps which need to be physically coupled to an outside source of pressurized fluid.
According to the scientists, the new pumps were put through fourteen million cycles and have so far shown no signs of leaking.
Moreover, their performance has surpassed that of state-of-the-art 3D-printed miniature liquid pumps and even compares well with miniature commercial vacuum pumps.
Image and content: Luis Fernando Velásquez-García/MIT