Free-Form Three-Dimensional Integrated Circuits on a Thread Using Organic Eutectogel-Gated Electrochemical Transistors

Existing flexible electronics are typically planar and visually conspicuous. In this work, the authors present a new paradigm: free-form three-dimensional integrated circuits (ICs) built primarily on a single textile thread, offering exceptional flexibility and discrete integration. Millimeter-scale transistors are assembled easily as daisy chains on a thread and utilize deep eutectic solvent gels or eutectogels as nonvolatile dielectrics for gating organic electrochemical transistors. The eutectogels provide stable transistor performance without the need for encapsulation and make the Organic Eutectogel-Gated Electrochemical Transistor (OEGET) a promising candidate for flexible electronics. Complex analog ICs, such as single-stage and multistage amplifiers, can be realized on a single thread that can easily fold and bend out of the plane of stretching for true three-dimensional flexibility. An all-thread-based device that uses a thread-based strain sensor and a thread-based integrated circuit for eye motion and respiration monitoring is also presented.