High Gauge Factor Research Articles

Fabrication, characterization, and repair of nanocarbon-loaded aircraft paint-based sensors for real-world SHM: studies at the laboratory scale

There has been considerable interest in piezoresistive nanocarbon-loaded polymer films for structural health monitoring, including damage detection and strain monitoring. While good performance has been demonstrated, issues related to practical implementation have received less attention. Here we present sensors made from exfoliated graphite nanoplatelets (xGnP) incorporated into a commercial paint that is applied to Sikorsky aircraft. A formulation and a fabrication method are developed that deliver high piezoresistive strain sensitivity alongside mechanical integrity. At approximately 7 wt% xGnP, the gauge factor in tension is in the range of 30–55, and the effectiveness of the sensors for damage monitoring is demonstrated by the detection of perforations. To obtain a paintable solution, key considerations in choosing the solvent employed for introducing the nanocarbon are compatibility and the ability to keep the nanocarbon suspended, which is achieved using ethyl acetate. The ability to form sensors in situ on aircraft structures requires an uncomplicated method of making robust electrical connections, which is demonstrated here using embedded copper mesh. The strong, often nonlinear, environmental sensitivity of polymer-nanocarbon materials must also be considered in applications; here, increasing temperature and humidity both raise sensor resistance. This work shows that a second, unstrained reference sensor would work well for automatic compensation. Lastly, a method for effecting a repair that employs standard processes and maintains the high gauge factor is demonstrated. With these advances, the paint-xGnP sensors are ready for in-the-field testing on aircraft.

Stretchable hybrid platform‐enabled interactive perception of strain sensing and visualization

AbstractHuman–machine interactive platforms that can sense mechanical stimuli visually and digitally are highly desirable. However, most existing interactive devices cannot satisfy the demands of tactile feedback and extended integration. Inspired by the mechanoluminescence (ML) function of cephalopod skin and the sensitive perception of microcracked slit‐organs, a bioinspired stretchable interactive platform is developed by designing a stretchable poly(styrene‐block‐butadiene‐block‐styrene)/fluorescent molecule (SFM) composite followed by the in situ polymerization of pyrrole (Py) and deposition of carbon nanotubes (CNTs), which possesses a simple multilayered structure and quantitatively senses the applied strains via the variations of digital electrical resistance and visual fluorescence intensity. Using the strain‐dependent microstructures derived from the synergistic interactions of the rigid PPy/CNTs functional layer and SFM, the SFM/PPy/CNTs‐based platforms exhibit excellent strain‐sensing performance manifested by a high gauge factor (GF = 2.64 × 104), wide sensing range (~270%), fast response/recovery time (~155/195 ms), excellent stability (~15,000 cycles at 40% strain), and sensitive ML characteristics under ultraviolet illumination. Benefiting from the novel fusion of digital data and visual images, important applications, including the detection of wrist pulses and human motions, and information dual‐encryption, are demonstrated. This study demonstrates the superiority of advanced structures and materials for realizing superior applications in wearable electronics.

Electrical, mechanical and damage self-sensing properties of basalt fiber reinforced polymer composites modified by electrophoretic deposition

In this work, basalt fiber reinforced polymer (BFRP) with enhanced electrical, mechanical properties and in-situ damage self-sensing capability was prepared using carboxylic carbon nanotubes (COOH-CNTs) modified BF fabrics via electrophoretic deposition (EPD) at different voltages. The BFRP with BF fabrics modified at a deposition voltage of 20 ​V (EPD20-BFRP) showed the lowest electrical resistivity. Compared with unmodified BFRP, the tensile and flexual moduli of EPD20-BFRP increased by 37.5 ​% and 14.9 ​%, respectively. Single-layer EPD20-BFRP exhibited a high gauge factor (GF) of 44.3 during tensile damage self-sensing. The acoustic emission (AE) signals during tensile and flexual damage process agreed well with the relative resistance changes (RRC), which confirmed different damage stages within loading process, such as elastic deformation, damage evolution, crack coalescence, and complete fracture. In addition, the multi-layer BFRP containing a single-layer EPD20-BFRP on the upper or lower surface of laminate exhibited distinct electrical signal responses subjected to the flexural loading.

Facile and direct 3D printing of smart glove for gesture monitoring

The distinctive characteristics of electrically conductive fabrics, including their flexibility, breathability, and comfort, have led to their recognition as a viable substitute for silicon wafers in wearable electronics. However, the difficulty of constructing sensors with three-dimensional (3D) structure on woven fabrics significantly limits their sensitivity and sensing range. Layer-by-layer 3D printing of entire smart textile sensing components has enabled the development of high-performance sensors with enhanced sensitivity and sensing range. This research endeavors to produce a smart glove with superior performance by incorporating strain and pressure sensors by 3D printing a composite conductive ink, consisting of multi-walled carbon nanotubes (MWCNTs), graphene nanosheets (GNSs), fumed silica (FSiO2) and Ecoflex, and encapsulated ink directly onto a commercially available fabric glove. The 3D structure of the sensing layer and the sensing material were intentionally designed to achieve desired performance. The smart glove demonstrates a high gauge factor (GF ∼ 35) and a strain range of 0–50% for strain detection. Additionally, it exhibits a high sensitivity of ∼0.07 kPa−1 and a sensing range of 1000 kPa for pressure examination, which facilitates precise detection of finger bending angles and fingertip contact pressures. The smart glove also shows excellent linearity, repeatable resistance response, favorable cycling characteristics in both strain and pressure detecting, and were unaffected by temperature and humidity. The combination of the smart glove with a Long Short-Term Memory (LSTM) deep learning model achieves a high accuracy (100%) for dynamic gesture recognition and manipulator control, demonstrating their potential for smart wearable electronics and human-computer interaction.

A Sensitive Strain Sensor Based on Multi-Walled Carbon Nanotubes/Polyaniline/Silicone Rubber Nanocomposite for Human Motion Detection

Strain sensors play a pivotal role in quantifying stress and strain across diverse domains, encompassing engineering, industry, and medicine. Their applicability has recently extended into the realm of wearable electronics, enabling real-time monitoring of body movements. However, conventional strain sensors, while extensively employed, grapple with limitations such as diminished sensitivity, suboptimal tensile strength, and susceptibility to environmental factors. In contrast, polymer-based composite strain sensors have gained prominence for their capability to surmount these challenges. The integration of carbon nanotubes (CNTs) as reinforcing agents within the polymer matrix ushers in a transformative era, bolstering mechanical strength, electrical conductivity, and thermal stability. This study comprises three primary components: simulation, synthesis of nanocomposites for strain sensor fabrication, and preparation of a comprehensive measurement set for testing purposes. The fabricated strain sensors, incorporating a robust polymer matrix of polyaniline known for its exceptional conductivity and reinforced with carbon nanotubes as strengthening agents, demonstrate good characteristics, including a high gauge factor, stability, and low hysteresis. Moreover, they exhibit high strain sensitivity and show linearity in resistance changes concerning applied strain. Comparative analysis reveals that the resulting gauge factors for composite strain sensors consisting of carbon nanotubes/polyaniline and carbon nanotubes/polyaniline/silicone rubber are 144.5 and 167.94, respectively.

3D Printing Assisted‐Fabrication of Low‐Temperature Strain Sensors with Large Working Range and Outstanding Stability

Recently, low‐temperature wearable strain sensors, referring to those working at sub‐zero temperatures, are attracting increasing attentions. However, the fabrication of low‐temperature strain sensors with large working ranges, high sensitivity, and good stability remains a major challenge. In this study, a novel low‐temperature wearable strain sensor is fabricated by depositing the silver nanoplates (Ag NPs)/carbon nanotubes (CNTs) composite onto a cured silicone (DS) substrate that is constructed by using a 3D printing technology. The synergistic effect of the Ag NPs with positive temperature coefficient of resistance (TCR) and the CNTs with negative TCR enable the Ag NPs/CNTs/DS strain sensor's TCR value (−1.16 × 10−5 K−1) to approach zero. The Ag NPs/CNTs/DS strain sensor demonstrates a high gauge factor over a large working range (0–100%) and fast response and recovery rates. Simultaneously, the Ag NPs/CNTs/DS strain sensor displays outstanding reproducibility and long‐term stability at −40 °C as well as excellent temperature cycling resistance under cyclic temperature of −40 to 60 °C. The Ag NPs/CNTs/DS strain sensor is further validated by incorporating into a wireless sensing system for remotely monitoring various human activities at −40 °C. This work provides wearable strain sensors for monitoring human‐machine interaction under low‐temperature condition.

All‐Weather Self‐Powered Intelligent Traffic Monitoring System Based on a Conjunction of Self‐Healable Piezoresistive Sensors and Triboelectric Nanogenerators

AbstractA self‐powered and sustainable traffic monitoring system is highly required for future urban development. Herein, self‐healable piezoresistive sensors and triboelectric nanogenerators (TENGs) are constructed by in situ polymerization of polyvinyl alcohol‐polyacrylamide double network hydrogel in the presence of sodium alginate and tannic acid‐modified cellulose nanocrystals (denoted as PPC) for all‐weather self‐powered intelligent traffic monitoring applications. Because of hydrogen bonding and boron ester bonding, the resultant PPC‐based strain sensor can rapidly self‐heal and restore its sensing ability within 1 min with a self‐healing efficiency of 97.4%. Based on piezoresistive effect, the ions in sodium alginate endow the PPC‐based strain sensor with a relatively high gauge factor of 8.39, which can monitor the motion and fatigue of drivers. Based on triboelectrification effect, the PPC‐based TENG sensor can detect instantaneous vehicle speed, judge traffic accident liability, evaluate vehicle weight, and alert the driver to prevent accidents caused by drowsy driving. After partially replacing water in the PPC with glycerin, the resulting PPC‐based TENG sensor exhibits stable performance at temperatures ranging from ‐30 to 40 °C, ensuring its all‐weather monitoring ability. The all‐weather and self‐powered intelligent traffic monitoring system is promising for ensuring the security of future cities.

Piezoresistive Performance of a Compliant Scalable Sensor Made of Low‐Cost Exfoliated Graphite Polymer Composites

Compliant sensors have drawn considerable interests in human–robot interactions. However, it is still challenging to obtain reliable and reproducible performance at reduced costs, especially for scaled‐up sensing applications. This work investigates the piezoresistive performance of a low‐cost, scalable sensor, which is made by spray coating exfoliated graphite natural rubber latex composites (EG/latex) over an elastomeric substrate. The EG/latex sensor provides a uniform distribution in the sheet resistance (variation below 4%) over a large 10 cm × 10 cm area. The stabilized piezoresistive response under cyclic tests is found highly related to both the filler concentration and the strain region. The 8 wt% and the 10 wt% sensors show nonlinear piezoresistive response, while the 25 wt% sensor exhibits the best linearity with a high gauge factor (7.6) and the lowest hysteresis (0.043) under a maximum strain of 60%. The distinct piezoresistive behavior is found attributed to the different levels of microbreakage under the applied strain. Scalable sensing performance is demonstrated on a hand‐size glove spray‐coated with 25 wt% EG/latex. Effective localization of contacts over the continuous sensing glove is achieved via the technique of electrical impedance tomography, validating the potential of the cost‐competitive EG/latex sensor for scalable sensing applications.

A high-sensitivity wearable flexible strain sensor based on three-dimensional twist-like network structure

With the rapid development of the flexible electronics field, flexible pressure sensors are widely used inwearable devices, medical monitoring and other fields. However, it is still a huge challenge to design a sensor with highsensitivity, low cost and a simple manufacturing process. In this work, we report a flexible strain sensor based on discarded mask straps (MS) with a unique three-dimensional (3D) twist-like network structure. Multi-walled carbon nanotubes (MWCNTs)/carbon nanoparticles (CN)/MS composites were prepared by a simple dip-drying method and encapsulated using a medical Polyurethane (PU) film. It is founded that the fabricated MWCNTs/CN/MS/PU flexible strain sensor (MCMP-FSS) exhibits a high gauge factor (GF) of 13,928 and advanced performance with a large sensing range of 0%–72%. Moreover, good water-repellent harmony and various types of stimuli over 1000 cycles were obtained for the MCMP-FSS. Benefiting from the unique 3D twist-like network structure and the MWCNTs/CN synergistic conductive network, MCMP-FSS also has broad application prospects in the fields of human motion detection, encrypted communication, and natural human-robot interaction.

Self-Healable PEDOT:PSS-PVA Nanocomposite Hydrogel Strain Sensor for Human Motion Monitoring.

Strain sensors based on conducting polymer hydrogels are considered highly promising candidates for wearable electronic devices. However, existing conducting polymer hydrogels are susceptible to aging, damage, and failure, which can greatly deteriorate the sensing performance of strain sensors based on these substances and the accuracy of data collection under large deformation. Developing conductive polymer hydrogels with concurrent high sensing performance and self-healing capability is a critical yet challenging task to improve the stability and lifetime of strain sensors. Herein, we design a self-healable conducting polymer hydrogel by compositing poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) nanofibers and poly(vinyl alcohol) (PVA) via both physical and chemical crosslinking. This PEDOT:PSS-PVA nanocomposite hydrogel strain sensor displays an excellent strain monitoring range (>200%), low hysteresis (<1.6%), a high gauge factor (GF = 3.18), and outstanding self-healing efficiency (>83.5%). Electronic skins based on such hydrogel strain sensors can perform the accurate monitoring of various physiological signals, including swallowing, finger bending, and knee bending. This work presents a novel conducting polymer hydrogel strain sensor demonstrating both high sensing performance and self-healability, which can satisfy broad application scenarios, such as wearable electronics, health monitoring, etc.

Synthesis of UV-curable disulfide functionalized polysiloxane for stretchable gold electrodes with microcrack

Stretchable electrodes prepared by conductive layer and elastomer were widely applied in sensors, flexible electronic devices and health detections. The microcracks in conductive layer strained synergistically with the elastomer, achieving linearly changing of conductivity with stretch. However, the interactions between the metal conductive layers and the substrates need to be enhanced for synergistical strain. In addition, the preparation of stretchable electrode with both high gauge factor (GF) and high stretchable conductivity is still a challenge. The study reported the synthesis of lipoic acid functionalized polysiloxane elastomer (LFPSE), which adhered gold nanoparticles to prepare stretchable electrodes. Elastomer were cured through thiol-ene click polymerization and stretchable electrode was prepared through evaporating gold nanoparticles on LFPSE in vacuum. S-Au bond was characterized by Raman spectroscopy and XRD. Tensile conductivity was performed through microcrack propagation of Au. The conductivity of the LFPSE stretchable electrode increased linearly with a maximum strain of 112.7%, and the GF was 127.89. Finally, LFPSE stretchable electrode was applied to detect muscle movement. The study of UV curable polysiloxane elastomer based on thiol-ene with S-Au interaction provided a potential application in wearable flexible electronic devices and stretchable electrodes.

Transparent single crystal graphene flexible strain sensor with high sensitivity for wearable human motion monitoring

Human-machine interfaces, smart glasses, touch screens and some electronic skins all require highly transparent and flexible strain sensing components. Flexible strain sensors usually use microstructures or porous active materials to improve sensitivity and response speed, resulting in low transparency of the device. Graphene has attracted extensive attention due to its special physical properties, especially excellent flexibility, and high transmittance. However, previous studies found that it is difficult to obtain high gauge factor in graphene. Thus, graphene cannot be used to monitor subtle deformations. Although previous research has shown that the strain sensors based on the combination of graphene and other materials have high sensitivity, but lack of transmittance. In this paper, we report a single-crystal graphene (SCG) strain sensor fabricated by encapsulating single-crystal hexagonal graphene in a flexible substrate. The strain sensor shows excellent performance with a high gauge factor (16.9) because it is not affected by wrinkles, grain boundaries and additional layers. Further, the strain sensor retains the advantage of high light transmittance of graphene. This sensitive SCG strain sensor has been demonstrated to detect a range of human motions, including finger gestures, tiny vibration of different sounds and heartbeats with high performance. This work further confirms the application of graphene in strain sensors, and provides new ideas for the research of graphene-based transparent strain sensors.

Strain-Driven Negative Resistance Switching of Conductive Fibers with Adjustable Sensitivity for Wearable Healthcare Monitoring Systems with Near-Zero Standby Power.

Recently, one of the primary concerns in e-textile-based healthcare monitoring systems for chronic illness patients has been reducing wasted power consumption, as the system should be always-on to capture diverse biochemical and physiological characteristics. However, the general conductive fibers, a major component of the existing wearable monitoring systems, have a positive gauge-factor (GF) that increases electrical resistance when stretched, so that the systems have no choice but to consume power continuously. Herein, a twisted conductive-fiber-based negatively responsive switch-type (NRS) strain-sensor with an extremely high negative GF (resistance change ratio ≈ 3.9× 108 ) that can significantly increase its conductivity from insulating to conducting properties is developed. To this end, a precision cracking technology is devised, which could induce a difference in the Young's modulus of the encapsulated layer on the fiber through selective ultraviolet-irradiation treatment. Owing to this technology, the NRS strain-sensors can allow for effective regulation of the mutual contact resistance under tensile strain while maintaining superior durability for over 5000 stretching cycles. For further practical demonstrations, three healthcare monitoring systems (E-fitness pants, smart-masks, and posture correction T-shirts) with near-zero standby power are also developed, which opens up advancements in electronic textiles by expanding the utilization range of fiber strain-sensors.

Hybrid assembly of conducting nanofiber network for ultra-stretchable and highly sensitive conductive hydrogels

Conductive hydrogels have attracted extensive attention owing to their promising application prospects in flexible and wearable electronics. However, achieving both high sensitivity and mechanical robustness remains challenging. Herein, a novel and versatile conductive hydrogel based on the hybrid assembly of conductive cellulose nanofiber (CNF) networks has been designed and fabricated. Assisted by the templating effect of CNFs and stabilizing effect of negatively charged poly(styrene sulfonate) (PSS), conducting polymer poly (3, 4-ethylenedioxythiophene) (PEDOT) was self-organized into three-dimensional nanostructures which constructed a robust conductive network after in-situ oxidative polymerization. The unique structure derived from CNF bio-template endowed polyacrylamide (PAM) hydrogels with improved electrical conductivity and excellent mechanical performance. As a result, the as-fabricated CNF/PEDOT:PSS/PAM hydrogel exhibited an ultimate tensile strain of 1881% and toughness of 3.72 MJ/m3, which were 4.07 and 8.27 times higher than the CNF-free hydrogel, respectively. More significantly, the resultant hydrogel sensor showed highly desirable sensing properties, including remarkable sensing range (1100%), high gauge factor (GF = 5.16), fast response time (185 ms), and commendable durability, as well as good adhesiveness. Moreover, the hydrogel sensor was able to distinguish subtle physiological activities including phonation and facial expression, and monitor large human body motions such as finger flexion and elbow blending. Besides, it was feasible to integrate the strain sensor on the joints of robots to recognize complicated machine motion signals, showing potential in advanced human-machine interactions.

Wavy graphene mesh reinforced elastic composite films for strain and pressure sensing

Highly flexible and sensitive strain sensors, based on graphene mesh (GM) composite films, have been widely applied in wearable electronics. However, the pressure detection application for GM composite film is still a great challenge. Herein, we present a facile method to fabricate GM/ polydimethylsiloxane composite film with wavy structure for tensile strain and vertical pressure detection. The wavy film showed a broad detection range of strain (0 ∼ 20%), high gauge factor (4.3), and excellent reliability. Meanwhile, it could detect vertical pressures over an ultrabroad sensing range of 0 ∼ 1000 kPa with a sensitivity of 2.72 kPa−1. Demonstrations of sensing for vocalization, joint bending, pressing and walking suggesting great potentials for full-body motion monitoring.

Piezoionic SnSe Nanosheets‐Double Network Hydrogel for Self‐Powered Strain Sensing and Energy Harvesting

AbstractFlexible strain sensors have enormous potential in wearable devices, robots, and health monitoring equipment. However, the poor stretchability of strain sensors based on semiconductors and the low sensitivity of resistance change‐based hydrogel strain sensors hinders the comprehensive application. Herein, a flexible piezoionic SnSe‐hydrogel composite with an optimized structure and improved performance is designed. The piezoionic output rises nonlinearly as the applied force increases, with the piezoionic coefficient up to 1780 nV Pa−1 and −7.21 nA Pa−1. The composite can realize the continuous positioning in 1D space based on the piezoionic effect. It also demonstrates self‐powered characteristics, an ultrafast response speed of 6–8 ms, and a high gauge factor of 95.89. The sensor is exemplified to monitor fist clenching and finger bending, which has the potential to discriminate different joint movements. Meanwhile, the device can light up a light–emitting diode under pressure and bending. The as‐prepared piezoionic SnSe‐hydrogel device, having both high stretchability and sensitivity, may shed light on developing high‐performance flexible strain sensors and generators.

Study on the formulation of green/eco thick film piezo resistive paste for strain gauge application

Thick film piezo resistors, such as strain gauges fabricated using screen printing technology, are widely used for pressure-sensing applications. This paper reports the study of RuO2-based piezoresistive pastes formulation using lead-free glass frits for their potential application for strain gauges. Thermal analysis (TG/DTA) of the prepared glass frit and piezo resistor paste composition was performed to understand the thermal behavior of the paste and the glass transition temperature of the glass frit. The XRD patterns of the films revealed no variation in the conductive phase concentration concerning the firing temperature. SEM analysis of the glass frit powders and the RuO2 powder show submicron-sized agglomerated particles. Electrical measurements showed that the samples fired at 750 ​°C have high gauge factor values (GFL ​= ​18.08, GFT= 12.50), indicating that this is the most suitable firing temperature to achieve the high gauge factor in the present study.

Optimal design and fabrication of stable ordered porous conductive structure for flexible strain sensors with high sensitivity and linearity

The increasing utilization of wearable electronics in human-computer interaction and medical health urges the rapid development of flexible strain sensors. However, it is still a challenge to fabricate flexible strain sensors with high sensitivity, linearity, and stability. Herein, we presented a freezing/magnetic orientation approach to construct dual-ordered porous conductive networks based on the reduced graphene oxide (rGO)/Fe nanowire (NW)/carboxymethyl cellulose (CMC) to optimize the sensing performance of the flexible strain sensors. Owing to the stable and ordered porous conductive network constructed by ice template-assisted rGO and magnetic field-induced Fe NW, the sensing performances of rGO/Fe NW/CMC ordered network composite were significantly improved. The prepared rGO/Fe NW/CMC strain sensor demonstrated a high gauge factor of 112.44, which was 426.90 % and 108.06 % higher than the samples with only ordered Fe NW network and only ordered rGO network, respectively. Meanwhile, the rGO/Fe NW/CMC strain sensor presented a linearity of 0.99 and a stability over 3000 dynamic stretching cycles, which was better than the sample without Fe NW and ordered rGO network. Owing to the excellent sensing performance, the rGO/Fe NW/CMC strain sensors were successfully used to monitor the human gestures, indicating the potential as practical wearable devices for real-time motion detection in human-computer interaction and medical health.

A monolithically integrated microcantilever biosensor based on partially depleted SOI CMOS technology

This paper presents a monolithically integrated aptasensor composed of a piezoresistive microcantilever array and an on-chip signal processing circuit. Twelve microcantilevers, each of them embedded with a piezoresistor, form three sensors in a Wheatstone bridge configuration. The on-chip signal processing circuit consists of a multiplexer, a chopper instrumentation amplifier, a low-pass filter, a sigma-delta analog-to-digital converter, and a serial peripheral interface. Both the microcantilever array and the on-chip signal processing circuit were fabricated on the single-crystalline silicon device layer of a silicon-on-insulator (SOI) wafer with partially depleted (PD) CMOS technology followed by three micromachining processes. The integrated microcantilever sensor makes full use of the high gauge factor of single-crystalline silicon to achieve low parasitic, latch-up, and leakage current in the PD-SOI CMOS. A measured deflection sensitivity of 0.98 × 10−6 nm−1 and an output voltage fluctuation of less than 1 μV were obtained for the integrated microcantilever. A maximum gain of 134.97 and an input offset current of only 0.623 nA were acquired for the on-chip signal processing circuit. By functionalizing the measurement microcantilevers with a biotin-avidin system method, human IgG, abrin, and staphylococcus enterotoxin B (SEB) were detected at a limit of detection (LOD) of 48 pg/mL. Moreover, multichannel detection of the three integrated microcantilever aptasensors was also verified by detecting SEB. All these experimental results indicate that the design and process of monolithically integrated microcantilevers can meet the requirements of high-sensitivity detection of biomolecules.

Ultra‐Robust and Sensitive Flexible Strain Sensor for Real‐Time and Wearable Sign Language Translation

AbstractFlexible strain sensors with high sensitivity and high mechanical robustness are highly desirable for their accurate and long‐term reliable service in wearable human‐machine interfaces. However, the current application of flexible strain sensors has to face a trade‐off between high sensitivity and high mechanical robustness. The most representative examples are micro/nano crack‐based sensors and serpentine meander‐based sensors. The former one typically shows high sensitivity but limited robustness, while the latter is on the contrary. Herein, ultra‐robust and sensitive flexible strain sensors are developed by crack‐like pathway customization and ingenious modulation of low/high‐resistance regions on a serpentine meander structure. The sensors show high cyclic stability (10 000 cycles), strong tolerance to harsh environments, high gauge factor (&gt;1000) comparable with that of the crack‐based sensor, and fast response time (&lt;58 ms). Finally, the sensors are integrated into a wearable sign language translation system, which is wireless, low‐cost, and lightweight. Recognition rates of over 98% are demonstrated for the translation of 21 sign languages with the assistance of machine learning. This system facilitates achieving barrier‐free communication between signers and nonsigners and offers broad application prospects in gesture interaction.