Circular Kirigami Structure With Out-of-Plane Deformation and Implementation of Double-Side Strain Sensor by Ink-Jet Printing

Given their excellent stretchability and flexibility, kirigami-based strain sensors are pivotal in the development of flexible and stretchable electronic devices. Unlike material-based stretchable sensors, conventional kirigami strain sensors inefficiently transmit tensile stress to the electrodes, resulting in lower sensitivity. This study introduces a circular kirigami strain sensor capable of three-dimensional deformation. Using inkjet printing to deposit conductive material onto paper, we fabricate a rapid and cost-effective kirigami strain sensor. We calculated stress distribution using the finite element method to identify an electrode arrangement enhancing sensitivity. With the optimized electrode arrangement, the kirigami strain sensor’s sensitivity was 184% higher than a sensor with a simple meander design. Furthermore, to mitigate sensitivity loss from the kirigami’s dual structure experiencing tension and compression, we proposed using double-sided printing. The double-sided printed kirigami strain sensor’s sensitivity was 276% higher than the single-sided, unoptimized meander design sensor. Finally, we proposed a wearable weight scale, attachable to the hand, utilizing the circular kirigami strain sensor. The circular kirigami strain sensor we propose offers low cost, high flexibility, and stretchability, suggesting potential for innovative packaging and cushioning materials adaptable to various structures and movements.