Self-Aligned Laser Cut Organic Electrochemical Transistors

NU 2020-017

INVENTORS
Reem Rashid
Robert Ciechkowski
Jonathan Rivnay*

SHORT DESCRIPTION
Improved organic electrochemical transistor design for complementary inverters

BACKGROUND
Transistors are fundamental components for logic gates which are the basis of almost all computing applications.  One such logic gate is the complementary inverter, which requires two different types of transistors.  Transistors are generally made of metal semiconductors doped with rare earth metals, which can make them toxic or incompatible with biological systems.  Organic electrochemical transistors use polymers in contact with an electrolyte solution as the semiconducting material, which can enable applications such as chemical sensing in a biological environment.

ABSTRACT
Northwestern researchers have developed a new manufacturing method for organic electrochemical transistors (OECTs).  One common method to manufacture OECTs is through photolithography, where a substrate containing the active material is etched away with exposure to a specific pattern of light.  However, multiple steps are often required when photolithography is used, and there are often alignment issues between various contact points which reduce the efficiency of the OECT.   A new process to manufacture OECTs was developed using lasers to cut the necessary patterns on a substrate.  This laser-cutting process reduces the amount of steps necessary to make OECTs and also fixes alignment issues due to the nature of the method.   This technology would improve current state-of-the-art manufacturing methods for OECTs and quality of OECTs made, which can enable new applications in fields such as bioelectronics and chemical sensing.

APPLICATIONS

• Manufacture of organic electrochemical transistors
• Diagnostics and biological sensing
  • Detection and quantification of molecules in blood or other bodily fluids, such as glucose, antigens or virus components
• Bioelectronics
  • Can be incorporated into biological implants that require computational components

ADVANTAGES

• Simpler manufacturing process compared to photolithography methods
• Self-aligning process leads to more efficient transistors

PUBLICATIONS
Rashid RB, Ciechowski RJ and Rivnay J. (2020). Self-aligned, laser-cut organic electrochemical transistors. Flexible and Printed Electronics, 5(1), 014007.

IP STATUS
A US provisional patent has been filed.

Illustration of a laser-cut channel and the deposition of active material for an organic electrochemical transistor.