Fluid Equilibrium

 

Researchers at the Material Processes and Systems Group have developed a computationally-based manufacturing process that allows for variable pattern casting through the use of ferrofluid – a mixture of suspended magnetic nanoparticles in a carrier liquid. The capacity of ferrofluid to form intricate spike and labyrinthine packing structures from ferrohydrodynamic instabilities is well recognized in industry and popular science. We employ these instabilities as a mold for the direct casting of rigid materials with complex periodic features. This research was presented at the 2018 ACADIA conference in Mexico City.  More detailed information about the project can be found in the full conference paper, available here.

 

The variable states of ferrofluid are shown above: 1) Ferrofluid without a magnetic field 2) Ferrofluid exposed to a magnetic field, and 3) Ferrofluid and uncured epoxy resin exposed to a magnetic field. The image at right shows the fundamental components of casting process.

 

 

Using a bitmap-based computational workflow and an array of high-strength neodymium magnets with linear staging, we are able to program macro-scale pattern formation by modulating the magnetic field density within a single cast. Using this approach, it is possible to program specific patterns in the resulting cast tiles at both the micro- and macro-scale and thus generate tiled arrays with predictable halftone-like image features. The research team developed a range of image processing and pattern calibration strategies to predict the outcome of a given cast.

 

An actuator assembly with an epoxy cast tile on the upper platform (left), the arduino microcontroller and circuit (middle), and the digital interface developed in Grasshopper for Rhinoceros 5.0 (right).

 

 

The above detail images show the range of patterns generated in epoxy resin by varying the magnetic field strength, quantity of ferrofluid, and amount of casting medium. Each image field shows a 30 mm square sample area.

 

 

The above photograph shows an array of epoxy resin tiles used to recreate an image. Each tile measures 96 mm in width and height, used 225g of resin, and up to 25g of ferrofluid, resulting in a tile thickness of approximately 10 mm.

 

 

We have adapted this approach for a variety of materials typically used in the architecture, engineering, and construction industries (AEC) including epoxys, ceramics, and cements. Tile casts generated in a range of materials using the same magnetic field are shown above. Tiles B – G were spray-painted white to facilitate comparison between pattern geometries since remnant ferrofluid can cause staining or discoloration in untreated samples.


Project Team: Martin Bechthold, James Weaver, Allen Sayegh, Zach Seibold, Jonathan Grinham, Olga Geletina, Onyemaechi Ahanotu

For press enquiries contact Zach Seibold (zseibold@gsd.harvard.edu)

Font Resize