Dendrite-Inspired and 3D Printed Multidirectional Sensing Piezoresistive Metamaterials

Piezoresistive metamaterials fabricated via 3D printing have gained increasing attention due to their high flexibility and stability, making them suitable for a wide range of applications. However, conventional isotropic and planar designs of these metamaterials restrict their sensing capabilities to uniaxial detection, significantly limiting practical utility. In this study, a 3D piezoresistive metamaterial inspired by the 3D structure of dendrites beneath human skin, achieving multidirectional and multifunctional sensing capabilities is presented by controlling the distribution of different lattice micro cell types. These anisotropic piezoresistive metamaterials can be successfully fabricated by one-step digital light processing (DLP) 3D printing. When integrated with augmented reality (AR) systems, these customizable metamaterials enable seamless object interaction workflows encompassing 3D spatial localization, capture, and recognition through real-time virtual feedback. Furthermore, a digital twin system is implemented to enhance real-time visual feedback in AR and deliver an immersive operating experience for the user. This synergistic combination of anisotropic design and one-step 3D printing establishes a novel paradigm for developing metamaterials with multifunctional, multiregional, and multidirectional sensing capabilities.