Self-Assembled Functionally Graded Graphene Films with Tunable Compositions and Their Applications in Transient Electronics and Actuation

Tailoring Electrical Properties in Carbon Nanomaterial Patterns with Multimaterial Aerosol Jet Printing

Multimaterial aerosol jet printing offers a unique capability to freely mix inks with different chemical compositions in the aerosol phase, enabling one-step digital fabrication with tailored compositions or functionally graded structures, including in the x-y plane. Here, in situ mixing of two carbon nanomaterial inks with distinct electrical properties is demonstrated. By tailoring the mixing ratio of the constituent inks, electrical conductivity is modulated by 130×, and sheet resistance values for a single pass span approximately 2 orders of magnitude. The ability to manufacture components with tailored electrical properties offers significant value for hybrid and flexible electronic device applications, such as microelectronics packaging. Moreover, grading properties within a part provides a new dimension of design freedom for complex assemblies.

Soft Actuators Based On Carbon Nanomaterials

Inspired by the sophisticated design of biological systems, interest in soft intelligent actuators has increased significantly in recent years, providing attractive strategies for the design of elaborate soft mechanical systems. For the construction of those soft actuators, carbon nanomaterials were extensively and successfully explored for the properties of highly conductive, electrothermal, and photothermal conversion. This review aims to trace the recent achievements for the material and structural design as well as the general mechanisms of the soft actuators, paying particular attention to the contribution of carbon nanomaterials resulted from their diversified interplaying properties, which realized the flexible and dexterous deformation responding to various environmental stimuli, including light, electricity and humidity. The properties and mechanisms of soft actuators are summarized and the potential for future applications and research are presented.

Two-Phase-Interfaced, Graded-Permittivity Titania Electrical Insulation by Atmospheric Pressure Plasmas

Functionally graded materials (FGMs) exhibit unique properties and are expected to deliver outstanding and stable performance under extreme conditions. High-voltage, high-power FGM-based electric insulation commonly fails because of inadequate surface charge control (flashover) performance and stability of stacked layers of dielectric materials with graded permittivity ε_r. Here, we address these issues by interfacing the rutile and anatase TiO₂ layers on a ceramic with very different ε_r values of 110, 48, and 9, respectively, using scalable, environment-benign, and energy-efficient atmospheric pressure plasma processing. The FGM drastically reduces the maximum electric field along the optimized surface by 66% and increases surface flashover voltage by 36 %, while featuring a remarkable (120/180 days) long-term stability. The mechanisms of the plasma-enabled graded layer formation are presented, which can be used for precise engineering of FGMs for diverse applications in other fields.