Acceleration factors for flexible electronics in wearable applications from actual human body measurements

The increase in use of flexible electronics in wearable applications has prompted in analyzing the movement characteristics of human body under various day to day actions. The flexible electronics that are attached on the human body were tested for reliability under various conditions of human activity such as walking, jumping, squats, lunges and bicep curls. The human body motion data during these different actions were measured using a set of ten Vicon cameras to measure the position, velocity and accelerations of a standard full body sensor location of a human body. The reliability model presented in this study uses the angle variations of each joint in the human body for all the five human activities listed above. Statistical analysis on the variation of each joint angles were tested with hypothesis testing strategies with different subjects and with different human body actions as well. Acceleration factor modelling on the reliability of the electronics were carried out using test data of flexible electronics subjected to bending, twisting, stretching and folding experiments. These experiments were conducted on flexible electronics till failure with in-situ resistance measurements to monitor the changes in the board during each of these experiments. The experimental measurements of the boards were combined with the human body motion data to model the acceleration factor for each of these tests.