New approach to 3D printing improves neural interfaces

Researchers at Pusan National University have developed a new manufacturing process for neural interfaces. Microelectrothermoforming (μmETF) enables the production of flexible electrodes with three-dimensional microstructures that adapt better to neuronal tissue. The method could be important for artificial retinal implants and brain-computer interfaces.

Microelectrode arrays (MEAs) are used to measure and stimulate neuronal activity. Conventional MEAs are flat, which limits their adaptation to the curved structures of biological tissues. Existing techniques for integrating three-dimensional structures often require complex manufacturing processes with multiple process steps, which limits design flexibility.

The newly developed μmETF process is based on the principle of plastic thermoforming, a common technique for shaping plastic films.

“The idea for this study came from a simple observation of plastic lids on take-out coffee cups. I realized that this plastic forming method could be applied at a microscopic level to create 3D structures for neural electrodes,” says Associate Professor Joonsoo Jeong.

A thin polymer film with microelectrodes is heated and pressed against a 3D-printed mold. The material used is liquid crystalline polymer (LCP), which is characterized by its mechanical stability and biocompatibility. This enables the precise production of microstructures that optimize the contact between the electrode and nerve cells without impairing the electrical properties.

“Our 3D structures bring the electrodes closer to target neurons, making stimulation more efficient and precise,” Associate Professor Kyungsik Eom explains.

In the long term, the process could also be used in other areas of neurotechnology, such as implants for the brain, spinal cord or inner ear. μmETF could also open up new possibilities for brain-computer interfaces that are used to control prostheses or assistance systems.

The researchers are also investigating whether the technology can be used in other areas such as wearable electronic devices or microfluidic systems. The current focus is on the further development of manufacturing techniques to enable broader application in medicine.