Laser-patterned metallic interconnections for all stretchable organic electrochemical transistors

Area of Science:

• Materials Science
• Electronics Engineering
• Nanotechnology

Background:

• Standard thin-film microelectronic techniques lack comprehensive, simple, and accurate processes for fabricating fully stretchable organic electrochemical transistors (OECTs).
• Existing methods often fail to achieve high stretchability combined with low resistance in metallic interconnections for OECTs.

Purpose of the Study:

• To develop and present an innovative, accurate, and simple patterning process for creating fully stretchable OECTs.
• To achieve state-of-the-art stretchability in both metallic interconnections and the active organic layer of OECTs.
• To maintain high device performance metrics, such as transconductance and channel current, under strain.

Main Methods:

• Utilized a combination of laser ablation and thermal release tape for patterning stretchable metallic lines from aluminum tape, encapsulated in polydimethylsiloxane.
• Employed a photolithographic process to pattern the organic active area onto a stretchable substrate.
• Tuned the formulation of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) for optimal performance in the OECT active layer.

Main Results:

• Achieved highly stretchable metallic lines with up to 70% stretchability and ultra-low milliohms resistance.
• Fabricated OECTs with a maximum stretchability of 38% in the active layer.
• Maintained significant device performance, including transconductance up to 0.35 mS and channel current as high as 0.2 mA, under strain.

Conclusions:

• The developed process enables the fabrication of fully stretchable OECTs with unprecedented stretchability and maintained performance.
• This technique offers a simple and accurate method for producing stretchable sensors using standard microelectronic fabrication approaches.
• The findings pave the way for advanced wearable electronics and flexible sensor applications.