Design Framework for Polymer Nanocomposite Flexible Strain Sensor Adhesive Tape

Abstract

In the emerging flexible electronics field, flexible and wearable sensors play a crucial role. Though many reports focused on developing flexible sensors with novel materials, translational research is scarce. The present research focuses on a design framework for flexible strain sensors considering the design scalability, packaging feasibility and end users’ issues along with performance. To be specific, a flexible strain sensor tape framework is designed and developed using poly (vinylidene chloride-co-vinyl chloride) (PVDC-co-VC) and polystyrene sulfonate functionalized carbon nanotube (PSS-CNT) polymer nanocomposite with underneath adhesive coating and a copper contact pad atop the sensor. At the outset, numerical simulation is also carried out to understand the impact of uneven adhesive thickness profile on the sensor performance and emphasis the necessity of uniform adhesive coating underneath the sensor. Further, the PVDC-co-VC/PSS-CNT polymer nanocomposite is systematically optimized to find its percolation threshold to achieve its maximum performance. Later, the scaled-up long flexible strain sensor tape is developed and validated by measuring the gauge factor in multiple positions along the length of the sensor tape; it shows the uniform gauge factor value of 15.2±0.8 which ensures the sensor’s repeatability and reproducibility. As a testimony, the developed flexible strain sensor is demonstrated for wearable electronics applications with an indigenously developed IOT-enabled portable interface device. The present flexible strain sensor tape design framework supports scalability, and packaging feasibility and solves end users’ installation issues.