High Performance, Tunable Electrically Small Antennas through Mechanically Guided 3D Assembly

Abstract

As mobile/wearable devices with wireless data communication capabilities become increasingly miniaturized, sophisticated, and ubiquitous, [1][2][3][4][5][6][7] the interest in the development of antennas with large bandwidths and small sizes grows. Extensive academic and industrial studies focus on various designs for high efficiency electrically small antenna (ESA). An antenna is To address demands for increased data transmission rates, electrically small antennas (ESAs) that simultaneously offer large frequency bandwidths and small physical sizes are of growing interest. 3D layouts are particularly important in this context and among various 3D ESAs, systems that adopt hemispherical shapes are very promising, because they can occupy the entire Chu-sphere and offer outstanding electrical performance. Researchers have developed a few different approaches to fabricate high-quality hemispherical ESAs, but most have static layouts and fixed operating frequencies. Here, a mechanically guided 3D assembly approach is introduced for the design and fabrication of deformable hemispherical ESAs that can offer tunable, dynamic properties to adapt to changes in environmental conditions. The strategy exploits controlled compressive buckling of strategically patterned 2D precursor structures, as a low-cost and high-yield scheme that can exploit conventional, planar processing technologies and commercially available platforms. Combined numerical simulations and experimental measurements show outstanding performance characteristics in terms of the quality factor and radiation efficiency. Application of external tensile strains to elastomeric substrates for these systems allows them to be reshaped and reversibly tuned through a wide range of center frequencies.Mechanical testing under different loading conditions demonstrates the ability of these ESAs to accommodate large deformations.

Flexible and Stretchable Antennas for Biointegrated Electronics

“…Size, in particular, is important in wearable and/or biointegrated systems. Electrically small antennas (ESA) are defined by an electrical sizes that are less 0.5, [90] where the size corresponds to the product of the free-space wave number of the RF waves at the operating frequency and the radius of the smallest sphere that circumscribes the antenna. ESAs are of particular interest due to their large bandwidths and increased data transmission rates.…”

High‐Resolution 3D Printing of Freeform, Transparent Displays in Ambient Air

“…Overcoming this limitation potentially could result in significant applications beyond improving the scalability in device integration technologies. [22,[26][27][28][29] Herein, we report a hybrid 3D printing system that combines DLP and electrohydrodynamic jet (e-jet) printing for the production of transparent and freeform 3D optoelectronic devices Direct 3D printing technologies to produce 3D optoelectronic architectures have been explored extensively over the last several years. [5][6][7][8][9] One of the alternative technologies that can overcome the limitations of photolithography is direct 3D printing, which has been explored extensively during the last several years for purely additive operations in which functional inks are deposited only where they are required for the 3D structures.…”

Kirigami‐Enabled, Passive Resonant Sensors for Wireless Deformation Monitoring

“…In both cases, the strain causes a geometric change, which causes the resonant frequency of the LCR to shift, however, due to the design of these sensors, they can only report strains of 0–0.3, or in the case of ≈3 cm structures, a deformation of up to 1 cm. Stretchable antennas can also be used to measure deformation; these are primarily based on liquid metals, but recent works have also shown strategies for metallic deformable antennas . However, most examples require connected equipment to transmit data, which limits deployment and deformation tracking in dynamic systems .…”