RepRap: Blog

Bit of a blast from the past here, but someone was using dip pen techniques on the nanoscale (kinda) back in 2012! Their hardware was significantly different, but the feature size they demonstrated is encouraging for the μRepRap approach - particularly when we get to second generation microscale hardware. The deposition method has a name already, which I suppose I'd better start using. Dip Pen Nanolithography (DPN).

Here's the paper by one Marcel A.C. Thomas at MIT:

https://dspace.mit.edu/bitstream/handle/1721.1/75683/820011104-MIT.pdf

Thomas was trying to achieve something else: aligning large molecules dissolved in the ink by dragging them out with the pen tip, rather than just depositing blobs of resin in shapes. Illustration from the paper:

The positioning resolution achieved by their hardware was in the order of 50-60μm, so not miles away from μRepRap. However their aim was to create arrays of patches of aligned molecules rather than structures, so that was probably all they needed.

It does suggest though that as we start working on smaller scales we will have the opportunity to use the self-arranging abilities of some materials to "cheat" in the same way that RepRaps do by using commonly available fasteners and belt drives.