Out-of-plane electric whiskers based on nanocarbon strain sensors for multi-directional detection

Abstract

Conventional Si-based electronics cannot realize unique macroscale device structures for various applications such as robotics, healthcare, and Internet of Things concepts. For example, mimicking animal whiskers to sense environmental obstacles requires detection in multiple directions and an array structure without sacrificing mechanical flexibility and complexity. To address these challenges, this study proposes an out-of-plane electric whisker array using transferred-nanocarbon strain sensors in polydimethylsiloxane (PDMS). Eight directional force detection and a 3 × 3 array device proof-of-concept are demonstrated by monitoring the resistance change of an integrated strain sensor surrounding a whisker structure. Due to the embedded nanocarbon structure into PDMS, the sensor is mechanically robust and stable for long-time measurements. Although a three-dimensional device structure is used, sensor integration is realized via the simple device fabrication process, suggesting that an out-of-plane flexible integrated sensor platform has potential in future applications for macroscale flexible electronics without increasing complexity.