Facile material extrusion of 3D wearable conductive-polymer micro-super-capacitors

Directly printing 3D-structured conductive polymers (CP) allows the adaptable fabrication of electronic devices for variety of applications, including energy storage, energy harvesters, sensors, and electronic circuitry. However, previous attempts to 3D print CP relied on freeze-drying, a technique that increases the processing complexity and time span. Herein, a facile and accessible method that utilizes Super Absorbent Polymer (SAP) to formulate an ideal ink for Material Extrusion (MEX) is demonstrated by pre-concentrating commercial poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution to 12.72 wt% hydrogel at room temperature. This reduces the existing fabrication time by 12-fold, significantly improving its rapid processibility and the ability to transform CP from material to device. This technique creates multi-layered electrically conductive structures with feature size of 250 mu m. Further, the effectiveness of this technique can create high-performance micro-super-capacitors (MSCs) with the unprecedented ability to linearly control charge storage through layer deposition without sacrificing rate performance. The newly fabricated MSCs has a consistent high areal energy density of 3.8 mu Wh cm(-2) at power densities between 25 and 500 mu W cm(-2), suitable for powering wearable biomedical sensors, illuminating wristbands, and location trackers. Finally, the MSCs can be readily charged through both AC and DC mobile power source.

Automated summary

A simple and accessible method using a super absorbent polymer as ink is developed to directly 3D print conductive polymers. This technique significantly reduces processing time and improves the ability to create high-performance micro-supercapacitors, suitable for a variety of applications.