Strain‐Driven Auto‐Detachable Patterning of Flexible Electrodes

• DOI: 10.1002/adma.202202877
• Publication Date: 2022-05-31T12:12:43Z
• Authors: Zhisheng Lv; Changxian Wang; Changjin Wan; Renheng Wang; Xiangyu Dai; Jiaqi Wei; Huarong Xia; Wenlong Li; Wei Zhang; Shengkai Cao; Feilong Zhang; Haiyue Yang; Xian Jun Loh; Xiaodong Chen
• Keywords: :Materials::Functional materials [Engineering]; :Electrical and electronic engineering [Engineering]; Conductive Polymers; 01 natural sciences; Bacterial Cellulose; 0104 chemical sciences

AbstractFlexible electrodes that are multilayer, multimaterial, and conformal are pivotal for multifunctional wearable electronics. Traditional electronic circuits manufacturing requires substrate‐supported transfer printing, which limits their multilayer integrity and device conformability on arbitrary surfaces. Herein, a “shrinkage‐assisted patterning by evaporation” (SHAPE) method is reported, by employing evaporation‐induced interfacial strain mismatch, to fabricate auto‐detachable, freestanding, and patternable electrodes. The SHAPE method utilizes vacuum‐filtration of polyaniline/bacterial cellulose (PANI/BC) ink through a masked filtration membrane to print high‐resolution, patterned, and multilayer electrodes. The strong interlayer hydrogen bonding ensures robust multilayer integrity, while the controllable evaporative shrinking property of PANI/BC induces mismatch between the strains of the electrode and filtration membrane at the interface and thus autodetachment of electrodes. Notably, a 500‐layer substrateless micro‐supercapacitor fabricated using the SHAPE method exhibits an energy density of 350 mWh cm−2 at a power density of 40 mW cm−2, 100 times higher than reported substrate‐confined counterparts. Moreover, a digital circuit fabricated using the SHAPE method functions stably on a deformed glove, highlighting the broad wearable applications of the SHAPE method.