Application of Re-Entrant Honeycomb Auxetic Structure in Force Measurements

Abstract

Force measurement plays an important role in assessing the status of electromechanical system and the performance control. Force sensors are the most common devices that used for measuring force, and are made with various materials and fabrication methods. However, the components of most sensors are in contact with each other, which bring a lot of inconvenience to design and preparation the sensor, and also cause the interference and noise transmission between the substrate and conversion element. In this paper, a new force measurement method based on the auxetic structure is proposed. The scheme of this method consists of three parts, which are light source, auxetic structure and the solar cell. The auxetic structure can be regarded as a substrate and solar cell as a conversion element. These three parts are not in contact with each other. The basic principle of the proposed method is that the change of transmittance of the auxetic structure due to elastic deformation is transformed into the change of output current of the solar cell. The effectiveness of the proposed method is investigated by geometrical analysis and experiment. The sensitivity and linearity error of the proposed method based on the auxetic structure are 0.04mV/N and 8.17% respectively, while that based on the non-auxetic structure are 0.02mV/N and 14.78%. The results prove the feasibility of the proposed method and this study provides new structural insights for force sensors and presents future research directions.