NSF Award
2301693
Printed or additive manufacturing has application potential as a low-cost, high-resolution, fast prototyping of a range of complex circuits. Printed tunable devices proposed in this work will allow the electrical tuning of circuit functions, drastically reducing the cost, footprint, and weight of the overall circuitry compared to mechanically tunable electrical devices. These printed tunable electrical devices are critical to national security, especially radio communications. In addition, low-cost Internet of Things (IoT) and wearable devices will significantly benefit from the proposed tunable flexible electrical devices. However, currently, there are no tunable printable inks to fabricate tunable electrical devices on flexible substrates. In addition, existing printable materials need high-temperature processing (greater than 800 °C) to achieve the required tunability, which will damage most types of flexible substrates, such as plastics, paper, and fabrics. Multiple challenges and unique bottlenecks are associated with printable inks, and there are limited ongoing research efforts to solve these issues. This project will cover novel tunable materials syntheses, printable ink development, and the design, simulation, and fabrication of tunable electrical devices. This project will open a new paradigm of tunable flexible electronic devices. Both undergraduate and graduate students will directly benefit from this project, and the proposed educational outreach projects will enhance middle school students' interest and awareness of science and engineering careers. In addition, the proposed project's novel findings will be integrated into graduate-level printed electronics-related teaching.<br/><br/>This project will comprehensively advance the fundamental understanding of the utilization of sinterless Barium Strontium Titanate (BST) nanoparticles as a tunable material for flexible electronics. The composition of BST nanoparticles to achieve the highest possible dielectric constant and tunability at room temperature (without sintering) will be identified. An in depth investigation will be carried out to determine the effects of the Ba:Sr molar fraction, the size, and the packing density of BST nanoparticles on dielectric tunability. High-resolution X-Ray diffraction patterns of sinterless BST nanoparticles under an applied electric field will be used to investigate the correlation between the variation of lattice parameters and the dielectric tunability. This will give a greater insight into the dielectric tunability of sinterless BST nanoparticles, which have not been experimentally reported yet. Lowering the required bias voltage to less than 25 Volts is a significant achievement that enables the usage of printed tunable flexible devices in real-world applications, such as phase shifters, frequency-selective surfaces, and phased array antennas. These devices are not currently feasible for real-world applications. The proposed work will significantly advance the knowledge of sinterless BST nanoparticles as a tunable material, nanoparticle ink formulation for direct-write printing technologies, and fully printed tunable radio and microwave frequency devices on flexible substrates.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
