Fully Printed Ionic Diodes from Polymerizable Ionic Liquids

Area of Science:

• Materials Science
• Electrochemistry
• Bioelectronics

Background:

• Soft ionic diodes (SIDs) are key components in bioinspired iontronic devices.
• Traditional SID fabrication is manual, low-throughput, planar, and uses hydrogels prone to dehydration.
• Instability and performance loss are common issues with conventional SID electrolytes.

Purpose of the Study:

• To present a novel method for fabricating SIDs using 3D printing.
• To enable rapid, scalable manufacturing of SIDs with improved stability and geometry.
• To explore the potential of 3D-printed SIDs in advanced iontronic applications.

Main Methods:

• Developed solvent-free, polymerizable ionic liquid (pIL) inks for electrodes and electrolytes.
• Utilized a multi-ink 3D printing approach to fabricate SIDs with various geometries.
• Characterized SID performance using cyclic voltammetry and chronoamperometry.

Main Results:

• Successfully 3D printed SIDs with rectification ratios up to 46.
• Demonstrated geometry-, scan rate-, and time-dependent performance characteristics.
• Fabricated dense multidiode arrays (≈100 SIDs/cm2) with scalable current and voltage relationships.

Conclusions:

• 3D printing of pIL-based SIDs offers a rapid, scalable, and versatile fabrication route.
• The developed method overcomes limitations of traditional SID manufacturing, enhancing device stability.
• This approach facilitates the creation of complex iontronic devices for bioelectronics, neuromorphics, and soft robotics.