A Soft Pressure Sensor Array Based on a Conducting Nanomembrane

Abstract

Although skin-like pressure sensors exhibit high sensitivity with a high performance over a wide area, they have limitations owing to the critical issue of being linear only in a narrow strain range. Various strategies have been proposed to improve the performance of soft pressure sensors, but such a nonlinearity issue still exists and the sensors are only effective within a very narrow strain range. Herein, we fabricated a highly sensitive multi-channel pressure sensor array by using a simple thermal evaporation process of conducting nanomembranes onto a stretchable substrate. A rigid-island structure capable of dissipating accumulated strain energy induced by external mechanical stimuli was adopted for the sensor. The performance of the sensor was precisely controlled by optimizing the thickness of the stretchable substrate and the number of serpentines of an Au membrane. The fabricated sensor exhibited a sensitivity of 0.675 kPa−1 in the broad pressure range of 2.3–50 kPa with linearity (~0.990), and good stability (>300 Cycles). Finally, we successfully demonstrated a mapping of pressure distribution.

Soft CNT-Polymer Composites for High Pressure Sensors

“…To measure pressures in the range of 1–100 atm (approximately 0.1–10 MPa), an elastomer with a high Young’s modulus is needed to avoid complete compression within the pressure range, while sensors implementing Polydimethylsiloxane (PDMS) as the matrix have had success with implenting sensors over a wide range of pressures [ 14 , 15 , 16 , 17 ], and the pressure range of interest in this work far exceeds what PDMS is capable of. The maximum Young’s modulus of PDMS (as a function of the monomer to curing agent ratio) has been shown to be 2–3 MPa [ 18 , 19 ].…”

Skin-like Transparent Polymer-Hydrogel Hybrid Pressure Sensor with Pyramid Microstructures

“…In particular, soft e-skin, inspired by human skin, is used in robotics [9,10], skin-attachable electronics [11,12], and prosthetics [13][14][15] for biomimetic features such as stretchability, mechanical stability, and tactile sensing properties. For instance, stretchable and conductive polymers such as Ag nanowires [16], Ag flakes [17], carbon nanotubes (CNT) [18,19], PEDOT: PSS [20,21], nanomembranes [22,23], and liquid metals [24,25] have been used as e-skins. These polymers can monitor external stimuli such as strains, pressures, and temperatures and are mechanically robust and sufficiently stable in various environments to convert the stimuli into electrical signals.…”

Soft Mechanosensing via 3D Printing: A review

“…[9][10][11][12][13][14] Besides the seamless fabrication procedure, AM guarantees the opportunity to build actual 3D geometries, unlike previous 2D and 2.5D fabrication technologies. [15,16] This aspect is crucial and opens technological possibilities such as: 1) inspiration from natural sensory receptors to guide new morphological designs, 2) enhancing the deformation of the bulk material by incorporating voids through lattice-like geometries, and 3) investigating designs that enhance deformations in specific directions. These new design principles can pave the way to develop soft mechanical sensors able to discriminate different types of mechanical stimuli (in terms of, e.g., direction of the externally applied force, frequency, spatial features, etc.)…”