Shirsopratim Chattopadhyay1,John Labram2
Oregon State University1,University College London2
Shirsopratim Chattopadhyay1,John Labram2
Oregon State University1,University College London2
Flexible electronics is an emerging and rapidly blossoming technology that makes cheap, compact, light-weight devices with exotic form factors realizable. It’s expected to usher in a paradigm shift in diverse real-world applications of paramount importance, from medical technology to robotics to industrial Internet of Things (IoT).<br/>While a lot of research has been done on developing novel materials and manufacturing techniques for these devices, a comprehensive mathematical model to describe their behavior remains elusive. With the traditional Gradual Channel Approximation used for linear, flat thin film transistors (TFTs) still being the standard approach. This approximation will be invalid when the curvature of these devices becomes comparable to device dimensions. It’s vital to develop the mathematics that encapsulates this behavior before flexible electronics becomes fully commercial, as it forms the building block for further integrated circuit (IC) design with flexible TFTs.<br/>While there have been works on modelling the effect of physical stress due to deformation, such as those arising from bending and shear, on the electrical characteristics of TFTs, the effect of geometry itself is something seldom considered. In this work, we borrow on ideas from Differential Geometry and Point Set Topology to analytically develop a mathematical model that would predict electrical characteristics given the device geometry. We show that our model accurately predicts the expected behavior for a traditional linear TFT, as well as those on the surface of a cylinder and a sphere. It’s expected that the proposed model will guide future design and fabrication of ultrathin film chips and circuits. For flexible electronics to be commercially viable, it must be predictable under all circumstances.