All-printed capacitive pressure sensor with stability by dual-material fabrication

Purpose The purpose of this study is to overcome the challenges of assembly complexity and material incompatibility that hinder the stability of 3D printed soft capacitive pressure sensors, thereby facilitating their practical application in industry. Design/methodology/approach This research proposes a novel dual-material integrated direct ink writing (DIW) strategy. A mixture of PDMS and conductive carbon black is used for the electrode, while a face center tetragonal (FCT) structure is designed for the dielectric layer to enhance sensitivity. A customized switching module enables the continuous fabrication of both materials in a single, uninterrupted process. This approach ensures strong chemical bonding between the dielectric and electrode. Findings Experimental results confirm that the proposed method successfully fabricates sensitive and stable soft capacitive pressure sensors. The single-step process significantly simplifies manufacturing, and the material homogeneity achieved through the integrated DIW strategy markedly improves the interfacial bonding and overall robustness of the sensors. Originality/value The key originality of this work lies in the development of a seamless, single-step dual-material DIW strategy that simultaneously enables the precise fabrication of electrode-dielectric FCT layered structures. This integrated approach eliminates the need for post-assembly and addresses the issue of material incompatibility at its root, offering a new pathway for manufacturing reliable soft sensors.