Flexible capacitive pressure sensors using microdome like structured polydimethylsiloxane dielectric layers

Thouti, Eshwar; Chauhan, Kanika; Prajesh, Rahul; Farman, Mohd; Maurya, Ranjan Kumar; Sharma, Prashant; Nagaraju, A.

doi:10.1016/j.sna.2022.113393

Cited by 46 publications

(26 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Studies that applied nano– to micro–sized structure arrays to polymers have received much attention, to overcome this issue; the structure array provides the sensor with features that depend on its geometric shape. Previous studies have shown that performance is improved by utilizing arrays of nano/microstructures of basic 3D shapes, such as pyramids [ 209 , 210 ], domes [ 211 , 212 ], cones [ 213 ], and pillars [ 17 , 214 , 215 ]. These arrays are commonly applied to polymers such as PDMS [ 212 , 216 , 217 , 218 , 219 ].…”

Section: Structural Designs For Flexible Sensory Systemsmentioning

confidence: 99%

“…Previous studies have shown that performance is improved by utilizing arrays of nano/microstructures of basic 3D shapes, such as pyramids [ 209 , 210 ], domes [ 211 , 212 ], cones [ 213 ], and pillars [ 17 , 214 , 215 ]. These arrays are commonly applied to polymers such as PDMS [ 212 , 216 , 217 , 218 , 219 ]. In a recent study, a high sensitivity, wide detection range, long–term stability, and fast response time were achieved through basic structure modification and multilayer design.…”

Section: Structural Designs For Flexible Sensory Systemsmentioning

confidence: 99%

See 1 more Smart Citation

Flexible Sensory Systems: Structural Approaches

et al. 2022

View full text Add to dashboard Cite

Biology is characterized by smooth, elastic, and nonplanar surfaces; as a consequence, soft electronics that enable interfacing with nonplanar surfaces allow applications that could not be achieved with the rigid and integrated circuits that exist today. Here, we review the latest examples of technologies and methods that can replace elasticity through a structural approach; these approaches can modify mechanical properties, thereby improving performance, while maintaining the existing material integrity. Furthermore, an overview of the recent progress in wave/wrinkle, stretchable interconnect, origami/kirigami, crack, nano/micro, and textile structures is provided. Finally, potential applications and expected developments in soft electronics are discussed.

show abstract

Section: Structural Designs For Flexible Sensory Systemsmentioning

confidence: 99%

Section: Structural Designs For Flexible Sensory Systemsmentioning

confidence: 99%

Flexible Sensory Systems: Structural Approaches

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The aforementioned results prove that the HGCPS is applicable for practical wearable devices to monitor subtle, long-term, and low-frequency biosignals. The low detection limit, the sensitivity in low-pressure range, and the force range of the HGCPS are compared with other reported literature studies, − ,,,− as shown in Figure g,h and Table S1 (Supporting Information), which show that the HGCPS has a lower detection limit, a higher sensitivity in the low-pressure range, and a broad pressure range.…”

Section: Resultsmentioning

confidence: 69%

Capacitive Sensors with Hybrid Dielectric Structures and High Sensitivity over a Wide Pressure Range for Monitoring Biosignals

Feng

Wang

et al. 2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Various dielectrics with porous structures or high dielectric constants have been designed to improve the sensitivity of capacitive pressure sensors (CPSs), but this strategy has only been effective for the low-pressure range. Here, a hierarchical gradient hybrid dielectric, composed of low-permittivity (low-k) polydimethylsiloxane (PDMS) foam with low Young's modulus (low-E) and highpermittivity (high-k) MWCNT/PDMS foam with high Young's modulus (high-E), is designed to develop a CPS for monitoring biosignals over a wide force range. The foam-like structure with hybrid permittivity (low-k + high-k) is facilitated to improve the sensitivity, while the hierarchical structure with gradient Young's modulus (low-E + high-E) contributes to broadening the pressure sensing range. With the hierarchical gradient hybrid structure, the flexible pressure sensor achieves an enhanced sensitivity of 2.155 kPa −1 , a wide pressure range (up to 500 kPa), a minimum detection limit (50 Pa), and an excellent durability (>2500 cycles). As a demonstration, a venous thrombosis simulation and smart insole system are established to monitor venous blood clots and plantar pressures, respectively, which reveal potential applications in wearable medicine, sports health prediction, athlete training, and sports equipment design.

show abstract

“…Such linear behavior can also be seen in the sensor with a lamination layer. 18 It was observed that the edges of the sensor were the weakest points where the delamination process was initiated (see Video S1). Later, delamination was extended to the entire structure.…”

Section: ■ Results and Discussionmentioning

confidence: 98%

“…First, IO-PET electrodes were oxygen plasma-treated at 30 W for 60 s. More details can be found elsewhere. 18 The oxygen plasma-treated IO-PET electrode was carefully attached on the O 2 plasma-treated partially cured PDMS on the silicon mold with inverted micropyramids (procedure as described above). This assembly was cured at 80 °C for 1 h. After curing, the PDMS layer was strongly adhered to the IO-PET, which led to easy detachment from the silicon mold.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

All-Polydimethylsiloxane-Based Highly Flexible and Stable Capacitive Pressure Sensors with Engineered Interfaces for Conformable Electronic Skin

Farman

Surendra

Prajesh

et al. 2023

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Rapid development of flexible pressure sensors is indispensable in electronic skin to have the sensing capability to static and dynamic pressures. Besides high sensitivity and low hysteresis, the high flexibility and stability of these sensors are of paramount importance owing to the application requirement of conformable pressure mapping and rugged structure. Here, we describe a novel approach for highly flexible capacitive pressure sensors with engineered stable interfaces employing PDMS-based substrates and a micropyramidal dielectric layer, Au electrodes, and molecular adhesive. The sensor/matrix stack consists of five interfaces with strong interfacial adhesion achieved using MPTMS molecular adhesive and a partially cured PDMS lamination layer. A highly flexible capacitive pressure sensor capable of a wide pressure sensing range (up to 550 kPa) is developed with a high sensitivity (46.6 MPa–1 in ≤1 kPa), capability to sense pressure as low as 27 Pa, low hysteresis (4.05%), and high stability for large pressures (11,400 cycles @ 250 kPa). The sensor is successfully demonstrated for arterial pulse signal acquisition and performing a press task when attached on the forefinger. A flexible pressure sensor matrix of 4 × 4 pixels is developed. It can be flexed or crumpled; hence, it is conformably attached on a planar surface and a non-planar 3D-printed surface for single-point and multipoint pressure sensing. The sensor exhibited a maximum shear strain of 2.27 N before breakage. These highly flexible pressure sensor and matrix are also compared with a semi-flexible IO-PET electrode-based pressure sensor and matrix to clearly bring out the flexibility and stability advantages. The proposed process is simple and scalable and offers a conformably stable pressure sensor matrix for electronic skin development.

show abstract

Flexible capacitive pressure sensors using microdome like structured polydimethylsiloxane dielectric layers

Cited by 46 publications

References 38 publications

Flexible Sensory Systems: Structural Approaches

Flexible Sensory Systems: Structural Approaches

Capacitive Sensors with Hybrid Dielectric Structures and High Sensitivity over a Wide Pressure Range for Monitoring Biosignals

All-Polydimethylsiloxane-Based Highly Flexible and Stable Capacitive Pressure Sensors with Engineered Interfaces for Conformable Electronic Skin

Contact Info

Product

Resources

About