Kirigami-Enabled Microwave Resonator Arrays for Wireless, Flexible, Passive Strain Sensing

Abstract

Wireless and highly sensitive flexible strain sensors would have widespread application across a number of different fields. Here, the novel combination of two different metamaterials, one mechanical and one electronic, is demonstrated for its potential as such a sensor. An array of split-ring resonators (SRRs) were mounted on a bespoke kirigami sheet. The hybrid kirigami structure was designed specifically for the resonator array, in terms of both its physical dimensions and elastic response. Mechanical tests in concert with finite element modeling confirmed that the hybrid kirigami structure, containing two disparate kirigami motifs, exhibited a high range of strain and out-of-plane rotation without plastic deformation. The microwave sensing was designed to monitor variations in the S 11 response of the resonators as a function of out-of-plane kirigami hinge rotation. The mounted array of SRRs on the hybrid kirigami sheet could wirelessly detect changes in strain with high sensitivity (>30 MHz shift in resonant frequency; >30 dB shift in resonant amplitude) over a large range of strain, from 0.6 to 21.3%.

Strain Sensor with Enhanced Sensitivity for Wearable Electronics Using an Over‐Balanced Planar Elastomer

“…How to regulate the shrinkage effect based on the tunable Poisson's ratio of materials has been first reported in the seminal work of Lakes based on the classical elastically theory in 1987, [22] and then the elastic instability mechanism has been investigated. [23] Nowadays, many kinds of geometries and mechanisms have been proposed to achieve such effect, [24][25][26] and the typical structures adopted in the stretchable sensors are Kirigami structures [27][28][29] or auxetic architectures. [30][31][32] However, these structures are relatively complex and usually constructed using complicated manufacturing processes, which make a bottleneck in the practical development towards applications.…”

“…According to the classical elastic mechanism, a general stretchable OBPE substrate to enhance the sensitivity of the strain sensor is derived from the typical Kirigami-like structure. [27][28][29] The schematic structure of the OBPE sensor is shown in Figure 2a, which is composed of four supporting beams embedded into a flexible substrate to form the OBPE structure and a central sensing region deposited with conductive materials. The typical Kirigami structure (Figure S1, Supporting Information) is usually composed with the rigid beams, and each beam connected at the ends to form a hollow frame, which has the auxetic effect.…”

Smart Superhydrophobic Textiles Utilizing a Long-Range Antenna Sensor for Hazardous Aqueous Droplet Detection plus Prevention

“…They are low-cost, easy to fabricate, planar, compact, and compatible with complementary metal oxide semiconductors (CMOSs). ,− A microstrip planar microwave resonator sensor is composed of a split ring resonator (SRR) with a Gaussian-shaped frequency response. − Current research has highlighted utilizing these resonators to sense liquids, solids, and gases; ,,,− bacterial growth; ,− biomolecules; mechanical strain; and ice deposits, a testament to the diversity of possible sensing applications. However, in wireless sensing applications, planar microwave resonators require additional apparatuses such as antennas to act as a readout device for the remotely positioned sensing structure to transmit the sensed signals to a remote receiver. ,− In order to fabricate a compact and efficient device for sensing and transmitting the sensed signals, antenna-based microwave sensors are currently being introduced for long-range and wireless sensing applications.…”

Boosting the Tunable Microwave Scattering Signature of Sensing Array Platforms Consisting of Amorphous Ferromagnetic Fe2.25Co72.75Si10B15 Microwires and Its Amplification by Intercalating Cu Microwires

“…However, there are different compositional and shape configurations that belong to the microscale 2 of 16 that dazzle by their high versatility and variability in their properties, when they are subjected to an external stimulus (i.e., an applied electric and/or magnetic field, mechanical stresses, temperature, and a gas exposure) [1][2][3][4][5][6][7]. Specifically for the electromagnetic microwave technology, multifunctional materials with tunable properties by external stimuli are essential to progression in the field of sensing applications [4,8,9], microwave shielding systems [7,[10][11][12], wireless communication [13,14], antenna engineering [15,16], hyperthermia [17], and biomedical engineering [18][19][20]. The crossed control of the electromagnetic properties is appealing for advanced performances, involving the ability of modulating the electrical response by means of a magnetic field and conversely.…”