Japanese researchers have demonstrated a new type of resin that could be used in 3D micro-electrodes that interface with the brain. With the material, it's possible to micro-sculpt tiny objects that hold their shape after being "carbonized" at 800 degrees Celsius, which increases electrical conductivity; the process reduces models made with other available resins to a charred, shapeless blob.

The image above shows how the resin was used to reproduce the "Stanford bunny," a common test blueprint for 3D modeling and printing. Though the model on the right, seen after undergoing the carbonizing process, shrank by around 20 percent, it held its shape and integrity well. This allows for the creation of complex structures just a few micrometers across. The preferred technique for this is called two-photon polymerization, and involves "drawing" shapes onto the liquid resin with laser beams.

Electrodes can aid in therapy for Parkinson's, epilepsy, and depression

The team, led by Yuya Daicho of Yokohama National University, believes that the potential for brain interfaces is one of the most "promising applications." "Our method can provide complex 3-D electrode arrays," says Daicho, which could aid in therapy for conditions such as Parkinson's disease, epilepsy, and depression. Brain interfaces use rows of needle-shaped micro-electrodes and can be used to stimulate the brain by sending or receiving electrical signals from neurons.

Daicho's team plans to expand its research by testing the carbonizing process at higher temperatures; while this may destroy the resin structures, it's possible that they may turn into graphite, which would be an even more effective conductor. The team also wants to fabricate usable carbon micro-sculptures as a next step.