Nanoscale Contact Research Articles

Effects of Interfacial Imperfections on Nanoscale Adhesive Contact for Layered Medium

Depending on processing technologies and working conditions, imperfect bonding at the layer-substrate interface may occur, resulting in diverse mechanical responses compared to a perfectly bonded layer-substrate system. This study focuses on an imperfect interface under force-like conditions and incorporates it into a nanoscale adhesive contact model to explore the influences of interfacial imperfection on the adhesive contact behaviors of the layered medium. The adhesive contact model is formulated based on the Lennard-Jones (LJ) potential and the Hammaker summation method. The adhesive contact problem is addressed by solving the nonlinear surface gap equations between the contact bodies. The deformation within the gap equations, accounting for the influence of imperfections, is computed using the fast Fourier transform (FFT) algorithm. This study explores the influence of three stress jumping coefficients t1,t2 and t3, which quantitatively characterize the interfacial imperfection, and their coeffects with material parameters, including imperfection depth (layer thickness), adhesion work, and elastic modulus, on the adhesive contact behaviors of the layered medium. The findings underscore that the normal stress jumping coefficient t3 exerts the most significant impact, wherein a higher t3 value corresponds to a smaller adhesive force and a larger absolute contact approach, while tangential stress jumping coefficients t1 and t2 exhibit negligible influence. Decreasing t3 values correspond to varying interaction force-contact approach responses and contribute to alleviating contact stability in cases with large Tabor parameters. Interfacial imperfections manifest their influence by modifying the pressure-displacement response, with noticeable effects only within a specific imperfection depth range h¯<40. While the introduction of interfacial imperfections does not alter the fundamental impact of material parameters—such as imperfection depth, adhesion work ratios, and elastic modulus ratios—on adhesive force and contact approach, it does modify the magnitude of these effects. Furthermore, imperfections alter stress distribution, increasing maximal von Mises stress and causing stress concentration within the layer and at the interface. In summary, force-like imperfections reduce surface displacement, resulting in a smaller region of positive pressure and ultimately contributing to a larger adhesive force. However, this effect is accompanied by increased stress concentration at the imperfect interface. This heightened stress level poses a potential risk to the system's reliability.

Relaxing strong compatibility at atomistic-continuum interface: consistent linear coupling method

In this paper, we develop a brand-new coupling method called consistent linear coupling (CLC) with a view to resolving the difficulty of scaling down of the interface elements in the strong compatibility coupling (SCC), employed in the most accurate multiscale methods such as quasicontinuum. To this end, the CLC determines some conditions required to be satisfied to reproduce the SCC rigorously, regardless of the size of the interface elements. Therefore, it can produce a solution as accurate as the SCC with two additional features: significantly less computational cost and easier implementation. The CLC-based schemes are compared with well-known coupling methods including the SCC in terms of solving quasi-static 3D nanoscale contact and a 2D crystal under uniaxial tension. Numerical results demonstrate the superiority of the CLC with regard to the accuracy and computational efficiency.

The Effects of Humidity on the Velocity-Dependence and Frictional Ageing of Nanoscale Silica Contacts

This work examines the effect of environmental humidity on rate-and-state friction behavior of nanoscale silica-silica nanoscale contacts in an atomic force microscope, particularly, its effect on frictional ageing and velocity-weakening vs. strengthening friction from 10 nm/s to 100 μm/s sliding velocities. At extremely low humidities (≪1%RH\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\ll 1\\% RH$$\\end{document}), ageing is nearly absent for up to 100 s of nominally stationary contact, and friction is strongly velocity-strengthening. This is consistent with dry interfacial friction, where thermal excitations help overcome static friction at low sliding velocities. At higher humidity levels (10–40% RH), ageing becomes pronounced and is accompanied by much higher kinetic friction and velocity-weakening behavior. This is attributed to water-catalyzed interfacial Si–O-Si bond formation. At the highest humidities examined (> 40% RH), ageing subsides, kinetic friction drops to low levels, and friction is velocity-strengthening again. These responses are attributed to intercalated water separating the interfaces, which precludes interfacial bonding. The trends in velocity-dependent friction are reproduced and explained using a computational multi-bond model. Our model explicitly simulates bond formation and bond-breaking, and the passivation and reactivation of reaction sites across the interface during sliding, where the activation energies for interfacial chemical reactions are dependent on humidity. These results provide potential insights into nanoscale mechanisms that may contribute to the humidity dependence observed in prior macroscale rock friction studies. They also provide a possible microphysical foundation to understand the role of water in interfacial systems with water-catalyzed bonding reactions, and demonstrate a profound change in the interfacial physics near and above saturated humidity conditions.

Measuring interfacial thermal resistance across carbon nanotubes with in-situ electron microscopy: Unexpected reduction upon detachment and two orders of magnitude variations across diverse morphologies

The dynamic mechanical processes can notably impact the van der Waals (vdW) interaction at nanoscale contact interface and further interfacial thermal transport, but the experimental study is challenging. Here, by integrating a movable nanoprobe within an electron microscope, we dynamically adjusted the contact and detachment processes of vdW contact between two carbon nanotubes (CNTs), while measuring the thermal contact resistance (TCR) in situ with a nanofabricated thermal sensor. The TCR was found to span approximately two orders of magnitude at the moments when two CNTs just came into contact or detached. Surprisingly, during the initial stage of detachment, we observed that TCR unexpectedly further decreased by 65% instead of increasing. This decrease is attributed to the subtle alteration of exact contact interface in the circumferential direction, induced by the real-time observed rotation during the detachment process. A two-order magnitude difference in TCR for the diverse morphologies in static equilibrium between the same pair of CNTs due to the non-uniformity of the CNT surface structures can also support it. Our work provides valuable insights for dynamically modulating nanoscale interfacial thermal transport in various applications.

Friction Reduction Effect Caused by Microcontact and Load Dispersion on the Moth‐Eye Structure

Friction reduction is important from the viewpoint of energy problems and other issues. Frictional forces are known to vary depending on the material property, surface texture, and measurement scale. However, the effect of submicron‐sized moth‐eye structures prepared of robust plastic deformation materials on dry friction under high‐load conditions has not been investigated in detail. To investigate this, a copper moth‐eye structure is fabricated via electroforming for experimental measurements. Results from the friction tests reveal that real contact area increase is suppressed, as the friction coefficient of the moth‐eye structure decreases exponentially with increasing load. Further friction simulation demonstrates nanoscale contact between the structure's tip and indenter, indicating that the real contact area increase requires deformation of the moth‐eye structure itself (microcontact). However, the contact pressure on the surface is reduced by dispersing the load to the sides and bottom of the moth‐eye structure. Therefore, the suppression of real contact area increase can be attributed to the deformation suppression facilitated by load dispersion. These findings expand the possibilities for friction design with surface textures because they reveal the role of robustness due to submicron‐scale surface microstructure in reducing friction between plastic deformation materials.

Quantitative analysis of interface heat transport at the Si3N4/SiO2 van-der Waals point contact

Si3N4 and SiO2 have been widely used in lithium batteries and optical devices. The high energy density brought by device integration makes the interfacial heat transport at the nano scale a hot spot. To optimize interfacial heat transfer, the roughness of the device surface is continuously reduced down to the nanometer. However, due to the limitation of spatial resolution, it is difficult to realize the measurement of thermal boundary resistance in the case of nanoscale contact by the existing measurement means. There is a great discrepancy between the measurement and simulation results, making the optimization of interfacial heat transfer lack of experimental verification. In this paper, the measurement of thermal boundary resistance of Si3N4/SiO2 interface at the nano-scale, was firstly realized by the optimized 3ω-SThM system. The effect of air tunnel on the heat transfer between real surfaces was also analyzed. The progress made so far provides an effective experimental tool to measure interfacial heat transport at nanoscale point contact.

Functionalizing Surfaces by Physical Vapor Deposition To Measure the Degree of Nanoscale Contact Using FRET.

Adhesion between solid materials is caused by intermolecular forces that only take place if the adhering surfaces are at nanoscale contact (NSC) (i.e., 0.1-0.4 nm. To study adhesion, NSC can be evaluated with Förster Resonance Energy Transfer (FRET). FRET uses the interaction of compatible fluorescence molecules to measure the nanometer distance between bonded surfaces. For this, each surface is labeled with one fluorescence dye, named the Donor or Acceptor. If these molecules are in NSC, a nonradiative Donor-Acceptor energy transfer will occur and can be detected using FRET spectroscopy. Here, for the first time, we introduce an innovative concept of a FRET-based NSC measurement employing dye-nanolayer films prepared by a physical vapor deposition (PVD). The dye nanolayers were prepared by PVD from the vaporization of the Donor and Acceptor molecules separately. The selected molecules, 7-Amino-4-methyl-cumarin (C120) and 5(6)-Carboxy-2',7'-dichlor-fluorescein (CDCF), present high quantum yields (QY, QYD = 0.91 and QYA = 0.64) and a low FRET distance range of 0.6-2.2 nm, adequate for the study of NSC. The produced dye-nanolayer films exhibit a uniform dye distribution (verified by atomic force microscopy) and suitable fluorescence intensities. To validate the NSC measurements, FRET spectroscopy experiments were performed with bonded dye-nanolayer films prepared under different loads (from 1.5 to 140 bar), thus creating different degrees of NSC. The results show an increase in FRET intensity (R 2 = 0.95) with the respective adhesion energy between the films, which is directly related to the degree of NSC. Hence, this work establishes FRET as an experimental technique for the measurement of NSC, and its relation to surface adhesion. Additionally, thanks to the FRET dye-nanolayer approach, the method can be employed on arbitrary surfaces. Essentially, any sufficiently transparent substrate can be functionalized with FRET compatible dyes to evaluate NSC, which represents a breakthrough in contact mechanics investigations of soft and hard solid materials.

Mastering thermal transport across carbon nanotube contacts through morphological control

Thermally conductive nanomaterials hold great promise for applications in thermal management. However, the interfaces between nanomaterials can significantly impede heat flow, and a comprehensive understanding of thermal transport across nanoscale contacts is highly desired. Here, by integrating a movable nano-manipulator within an electron microscope with a nanofabricated thermal sensor, we adjusted the contact positions, overlapping length, and crossing angles between two carbon nanotubes (CNTs) as desired, while concurrently measuring the thermal contact resistance (TCR) at the van der Waals junction. The TCR far surpassed that of the studied 6 μm-long CNTs, particularly in contacts affected by inevitable nanoscale surface contamination. The TCR per unit area exhibited significant variations across different contact morphologies, spanning two orders of magnitude even for identical pairs of samples, attributable to structural non-uniformity within the CNTs. This in-situ approach and the notable morphology effects can guide the control of heat at the nanoscale.

Why is Superlubricity of Diamond-Like Carbon Rare at Nanoscale?

Hydrogenated diamond-like carbon (HDLC) is a promising solid lubricant for its superlubricity which can benefit various industrial applications. While HDLC exhibits notable friction reduction in macroscale tests in inert or reducing environmental conditions, ultralow friction is rarely observed at the nanoscale. This study investigates this rather peculiar dependence of HDLC superlubricity on the contact scale. To attain superlubricity, HDLC requires i) removal of ≈2nm-thick air-oxidized surface layer and ii) shear-induced transformation of amorphous carbon to highly graphitic and hydrogenated structure. The nanoscale wear depth exceeds the typical thickness of the air-oxidized layer, ruling out the possibility of incomplete removal of the air-oxidized layer. Raman analysis of transfer films indicates that shear-induced graphitization readily occurs at shear stresses lower than or comparable to those in the nanoscale test. Thus, the same is expected to occur at the nanoscale test. However, the graphitic transfer films are not detected in ex-situ analyses after nanoscale friction tests, indicating that the graphitic transfer films are pushed out of the nanoscale contact area due to the instability of transfer films within a small contact area. Combining all these observations, this study concludes the retention of highly graphitic transfer films is crucial to achieving HDLC superlubricity.

Interfacial processes underlying the temperature-dependence of friction and wear of calcite single crystals

HypothesisThis study posits that thermal effects play a substantial role in influencing interfacial processes on calcite, and consequently impacting its mechanochemical properties. ExperimentsThis work interrogates the temperature-dependence of friction and wear at nanoscale contacts with calcite single crystals at low air humidity (≤ 3–10 % RH) by AFM. FindingsThree logarithmic regimes for the velocity-dependence of friction are identified. BelowTc ∼ 70 °C, where friction increases with T, there is a transition from velocity-weakening (W1) to velocity-strengthening friction (S1). AboveTc ∼ 70 °C, where friction decreases with T, a second velocity-strengthening friction regime (S0) precedes velocity-weakening friction (W1). The low humidity is sufficient to induce atomic scale changes of the calcite cleavage plane due to dissolution-reprecipitation, and more so at higher temperature and 10 % RH. Meanwhile, the surface softens above Tc –likely owing to lattice dilation, hydration and amorphization. These interfacial changes influence the wear mechanism, which transitions from pit formation to plowing with increase in temperature. Furthermore, the softening of the surface justifies the appearance of the second velocity-strengthening friction regime (S0).These findings advance our understanding of the influence of temperature on the interfacial and mechanochemical processes involving calcite, with implications in natural processes and industrial manufacturing.

Selectivity and Growth Rate Modulations for Ruthenium Area‐selective Deposition by Co‐Reagent and Nanopattern Design

AbstractArea‐selective deposition (ASD) is a bottom‐up technique that provides numerous opportunities for nanoelectronic device fabrication. For example, advanced nano‐interconnect structures with barrierless metals like Ru in the contact holes can be created by Ru ASD with the bottom metals as growth surfaces and dielectrics as non‐growth surfaces. This work investigates Ru ASD by chemical vapor deposition (CVD) on industrially relevant substrates and nanopatterns and reveals how selectivity and growth rate are modulated by the CVD conditions and type of nanopattern. For low‐k dielectric/Cu substrate combinations, the selectivity reverses from metal‐on‐metal to metal‐on‐dielectric upon only changing the CVD co‐reagent from H2 to NH3. In contrast, NH3 is the preferred co‐reagent for SiO2‐TiN line patterns with critical dimension (CD) of 40 nm due to the more favorable adsorption and diffusion kinetics that cause growth rate and selectivity enhancement. Consistent with a diffusion‐mediated mechanism, the growth rate enhances even more for Ru CVD on nanoscale contact holes with CD of 10.5 nm, becoming 2.4 times higher as compared to unpatterned substrates. Thus, the ASD process changes drastically when pattern dimensions reach the nanoscale. The reported insights facilitate rational design of metal ASD processes for multiple applications in nanofabrication.

In Situ Optical Observation of Nanoscale Contact Spots Evolution Under Normal Loading

In Situ Optical Observation of Nanoscale Contact Spots Evolution Under Normal Loading

Effects of Temperature and Humidity on Energy Dissipation between Human Corneocytes and Nanoasperity Sliding Contacts.

Human haptic perception relies on the ability of sensory receptors underneath the skin corneocyte layer to sense external load, where adhesion and friction play an essential role in nanoscale solid-solid contact. Energy dissipation present at the surface interface due to the change of separation distance during sliding contact was uncovered, but the energy dissipation of human finger skin cell-nanoprobe contact under humidity and temperature conditions has not been investigated yet. In this paper, the energy dissipation of skin corneocyte-nanoprobe interface under variation of both humidity, 0.05-80%RH, and temperature ranging from 25 to 40 °C is directly measured by atomic force microscopy (AFM). Analytical models of dissipation energy for this nanomaterial interface mechanism are developed, and the results are compared to the measured values. AFM measurements of dissipation energy reveal that the amount of dissipated energy caused by water meniscus stretching monotonically increases with humidity and temperature, resulting in adhesion and friction decreases. The purposed analytical model represents that dissipation energy trend.

Microstructure and mechanical properties of Mg-Gd-Y-Zn-Zr alloy fabricated by cold metal transfer wire arc additive manufacturing

Wire arc additive manufacturing (WAAM) offers significant advantages in rapid manufacturing of complex integral parts. In this study, Mg-Gd-Y-Zn-Zr alloy deposited walls were fabricated by cold metal transfer (CMT) based WAAM. The interface bonding relationship between the additive zone and the substrate was studied, as well as the effect of the microstructure of the additive zone on the mechanical properties. The precipitated phase Mg24Y5 mainly distributed at the grain boundary was found in the additive zone of deposited walls, nano-scale contact interface and diffusion bonding interface were formed between β-Mg24Y5 and α-Mg (OR: [001]β-Mg24Y5//[10 1‾ 0]α-Mg), and a portion of the 18 R-LPSO phase to 14H-LPSO phase transition occurred in the substrate zone. In each layer of deposited metal, the bottom zone had a higher cooling rate than the top zone, which led to the supersaturation of rare earth elements. The precipitated phases between different deposition layers showed a decreasing trend from the bottom zone to the top zone due to the complex multiple thermal cycles in the additive manufacturing process. Compared with the cast Mg-Gd-Y-Zn-Zr alloy, the mechanical properties (UTS, YS and EL) of the Mg-Gd-Y-Zn-Zr alloy fabricated by WAAM were significantly increased. The ultimate tensile strength of the deposited walls along the travel direction was 227.27 MPa, and the elongation was 8.08 %.

A system of FRET dyes designed to assess the degree of nano-scale contact between surfaces for interfacial adhesion

HypothesisInterfacial adhesion caused by intermolecular forces only occur between surfaces at nano-scale contact (NSC), i.e., 0.1–0.4 nm and can be evaluated using Forster resonance energy transfer spectroscopy (FRET). For this, a suitable pair of fluorescent dyes must be selected, which spectroscopic properties will determine the FRET system performance. Here, we present a brand-new FRET dye system specifically designed to measure NSC in the distance range relevant for van-der-Waals and hydrogen bonding, i.e., below 1 nm. ExperimentsWe propose the FRET pair: 7-Amino-4-methyl-cumarin (C120) and 5(6)-Carboxy-2′,7′-dichlor-fluorescein (CDCF) with high quantum yield (QY, QYC120 = 0.91 and QYCDCF = 0.64) and a distance detection range of 0.6–2.2 nm (0.1 mM). Adhered-thin films with increasing NSC degrees are produced with ascending pressure from 1.5 to 150 bar. To validate the proposed FRET measurement, we are correlating the bonded films interfacial adhesion (separation energy) to the measured FRET intensity, indicating its degree of NSC. FindingsWe find that the proposed dyes are producing the desired FRET signal in adhered-thin films, for an interaction range of 0.6–2.2 nm, with high sensitivity due to the dye’s high quantum yields. The increasing adhesion in these films is only caused by its increase in NSC. We find that the adhesion strength, measured as the separation energy between the films, is correlated to the measured FRET signal. Hence, the introduced FRET system is accurately able to measure the degree of NSC between soft surfaces.

Nanoscale Schottky contacts to GaN: Theoretical study and a brief review

Nanostructured GaN materials, including nanowires and nanorods, are advantageous for nanoscale devices, owing to their higher surface-to-volume ratio than thin films. Despite the technological progress, there exist many issues to be solved for commercial applications. To realize nanostructured GaN devices, it is essential to figure out thoroughly the current transport mechanisms with regard to the nanoscale contact size. Experimental and theoretical studies have shown that the transport properties in nanoscale Schottky contacts are quite different from those in thin-film based contacts. In this article, theoretical models reported by other researchers are considered to calculate the potential profiles near the metal/GaN interfaces and the current transport mechanisms in nanoscale contacts are investigated. In addition, the results on the nanoscale Schottky contacts to GaN are reviewed to throw light on important issues in GaN nanoscale devices.

Nanoscale contact state design for nodal energy transfer at crossed Ag nanowires

The thermal conduction properties of the cross-junction formed by one pair of Ag nanowires were characterized using experiments and simulations. By laser-sintering crossed nanowires on a substrate on which the Ag ion complex ink was dispersed, we succeeded in visualizing the heat flow trajectory of the junction according to the application of energy. To theoretically understand the energy transfer behavior at the junctions, Ag nanowires with penta-twinned cross-sections were modeled by all-atom molecular dynamics simulations. The equilibrium and non-equilibrium simulation results showed the structural stability at the interface junction, convergence of heat flux in an unsteady state, and effective thermal conductivity of the entire system in a steady state. In particular, we focused on the dependence of the diameter on the nanoscale region, which is the most important design variable for Ag nanowires. Accordingly, a structure–property relationship governed by the nanoscale geometry of the junction was identified.

Evidence of Improved Thermal Stability via Nanoscale Contact Engineering in IGZO Source-Gated Thin-Film Transistors

Despite rapidly expanding interest in thin-film source-gated transistors (SGTs), the high-temperature dependence of drain current (TDDC) in devices comprising Schottky source barriers is delaying wide adoption. To reduce this effect, alternative source designs have been theorized. Specifically, introducing additional nanoscale layers at the source contact should facilitate the tunneling of charge carriers at the Fermi energy level with negligible TDDC. Here, we fabricate amorphous In <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text{2}}$</tex-math> </inline-formula> Ga <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text{2}}$</tex-math> </inline-formula> ZnO <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{\text{7}}$</tex-math> </inline-formula> tunnel-contact SGTs (TC-SGTs) with three times lower TDDC than polysilicon transistors with Schottky contacts. Numerical simulations help elucidate the control mechanisms. We show that the potential profile across the semiconductor in the bulk of the source-gate overlap region determines injection current, and the introduction of a thin interfacial layer at the contact reduces the role of the contact metal work function (WF) in current control and associated temperature effects. This device architecture adds improved thermal stability to the long list of SGT benefits, including low voltage saturation, power-efficient operation, high intrinsic gain, device-to-device uniformity, and robustness to mechanical and electrical stress.

Dissipation Mechanisms and Superlubricity in Solid Lubrication by Wet-Transferred Solution-Processed Graphene Flakes: Implications for Micro Electromechanical Devices.

Solution-processed few-layer graphene flakes, dispensed to rotating and sliding contacts via liquid dispersions, are gaining increasing attention as friction modifiers to achieve low friction and wear at technologically relevant interfaces. Vanishing friction states, i.e., superlubricity, have been documented for nearly-ideal nanoscale contacts lubricated by individual graphene flakes. However, there is no clear understanding if superlubricity might persist for larger and morphologically disordered contacts, as those typically obtained by incorporating wet-transferred solution-processed flakes into realistic microscale contact junctions. In this study, we address the friction performance of solution-processed graphene flakes by means of colloidal probe atomic force microscopy. We use a state-of-the-art additive-free aqueous dispersion to coat micrometric silica beads, which are then sled under ambient conditions against prototypical material substrates, namely, graphite and the transition metal dichalcogenides (TMDs) MoS2 and WS2. High resolution microscopy proves that the random assembly of the wet-transferred flakes over the silica probes results into an inhomogeneous coating, formed by graphene patches that control contact mechanics through tens-of-nanometers tall protrusions. Atomic-scale friction force spectroscopy reveals that dissipation proceeds via stick-slip instabilities. Load-controlled transitions from dissipative stick-slip to superlubric continuous sliding may occur for the graphene-graphite homojunctions, whereas single- and multiple-slips dissipative dynamics characterizes the graphene-TMD heterojunctions. Systematic numerical simulations demonstrate that the thermally activated single-asperity Prandtl-Tomlinson model comprehensively describes friction experiments involving different graphene-coated colloidal probes, material substrates, and sliding regimes. Our work establishes experimental procedures and key concepts that enable mesoscale superlubricity by wet-transferred liquid-processed graphene flakes. Together with the rise of scalable material printing techniques, our findings support the use of such nanomaterials to approach superlubricity in micro electromechanical systems.

Flexible Multimodal Sensors Based on Fibrous Porous Networks of Multiwalled Carbon Nanotubes and Polydimethylsiloxane for Sensing and Distinguishing Vertical and Shear Force

Wearable sensors are one of the key components in applications such as motion monitoring, smart medical care, and human-computer interaction systems. In the present work, we focus on the simultaneous improvements of flexible sensors in both performance and functionality. Here, with a porous fiber network of multi-walled carbon nanotubes (MWCNTs)–polydimethylsiloxane (PDMS) as an active layer, a flexible pressure sensor with ultra-high sensitivity and superior capability of identifying transverse shear force and temperature signals is designed and constructed. The fibral MWCNTs–PDMS piezoresistive layer was formed with a scouring pad (SP) fiber network as skeleton, and the PDMS thin layer formed by self-assembly can effectively increase the initial resistance. Attributing to the unique compressibility of the fibral porous network and the adjustable nanoscale contacts, the MWCNT-PDMS/SP sensor exhibits a wide detection range (0–360 kPa), and in particular, an ultra-high sensitivity (84,818.2 kPa–1 when <100 pa). Beyond the highly sensitive characteristics, the sensor also has a high shear-force sensitivity (GF = 6.15 under 0.05 N). The sensor can still maintain a relatively stable performance even after operating for more than 10,000 pressure cycles, showing as a potential candidate for the applications of electronic skin, intelligent robots, etc.