Tactile Detection Research Articles

Localizing strain via micro-cage structure for stretchable pressure sensor arrays with ultralow spatial crosstalk

Tactile sensors with high spatial resolution are crucial to manufacture large scale flexible electronics, and low crosstalk sensor array combined with advanced data analysis is beneficial to improve detection accuracy. Here, we demonstrated the photo-reticulated strain localization films (prslPDMS) to prepare the ultralow crosstalk sensor array, which form a micro-cage structure to reduce the pixel deformation overflow by 90.3% compared to that of conventional flexible electronics. It is worth noting that prslPDMS acts as an adhesion layer and provide spacer for pressure sensing. Hence, the sensor achieves the sufficient pressure resolution to detect 1 g weight even in bending condition, and it could monitor human pulse under different states or analyze the grasping postures. Experiments show that the sensor array acquires clear pressure imaging and ultralow crosstalk (33.41 dB) without complicated data processing, indicating that it has a broad application prospect in precise tactile detection.

Sensory retraining for Central Post-Stroke Pain: A subgroup analysis within a randomized controlled trial.

Explicit Sensory Retraining (SR) has been suggested for pain management in several neuropathic pain syndromes. To study the effectiveness of SR on Central Post Stroke Pain (CPSP) symptoms. A preplanned subgroup of 23 subjects post-stroke reporting central pain were randomized within a larger study, to receive either explicit sensory discrimination retraining (SR) (in subgroup n = 11) or implicit repeated exposure to stimuli (RE) (in subgroup n = 12), applied to the lower limb. Pain intensity measured by VAS, measures of sensory ability; balance and gait activities; and participation were assessed by a blinded assessor at four points in time. A group*time interaction effect was demonstrated (p = 0.04) for VAS, as for the SR treatment group VAS decreased from 56/100 to 23/100. Nine out of eleven subjects in the SR group demonstrated positive response to treatment. Pain alleviation was maintained at follow-up. A similar interaction effect was found for tactile threshold (p = 0.03). Significant improvement was noted for all other variables with no group differences. This study provides preliminary evidence to the clinically relevant positive effect of explicit sensory retraining for subjects with CPSP. The positive effect on tactile threshold detection could potentially indicate pain alleviation mechanisms.

A Machine Learning-Combined Flexible Sensor for Tactile Detection and Voice Recognition.

Intelligent sensors have attracted substantial attention for various applications, including wearable electronics, artificial intelligence, healthcare monitoring, and human-machine interactions. However, there still remains a critical challenge in developing a multifunctional sensing system for complex signal detection and analysis in practical applications. Here, we develop a machine learning-combined flexible sensor for real-time tactile sensing and voice recognition through laser-induced graphitization. The intelligent sensor with a triboelectric layer can convert local pressure to an electrical signal through a contact electrification effect without external bias, which has a characteristic response behavior when exposed to various mechanical stimuli. With the special patterning design, a smart human-machine interaction controlling system composed of a digital arrayed touch panel is constructed to control electronic devices. Based on machine learning, the real-time monitoring and recognition of the changes of voice are achieved with high accuracy. The machine learning-empowered flexible sensor provides a promising platform for the development of flexible tactile sensing, real-time health detection, human-machine interaction, and intelligent wearable devices.

Large-Scale Tactile Detection System Based on Supervised Learning for Service Robots Human Interaction

In this work, a large-scale tactile detection system is proposed, whose development is based on a soft structure using Machine Learning and Computer Vision algorithms to map the surface of a forearm sleeve. The current application has a cylindrical design, whose dimensions intend to be like a human forearm or bicep. The model was developed assuming that deformations occur only at one section at a time. The goal for this system is to be coupled with the CHARMIE robot, a collaborative robot for domestic and medical environments. This system allows the contact detection of the entire forearm surface enabling interaction between a Human Being and a robot. A matrix with sections can be configured to present certain functionalities, allowing CHARMIE to detect contact in a particular section, and thus perform a specific behaviour. After building the dataset, an Artificial Neural Network (ANN) was created. This network was called Section Detection Network (SDN), and through Supervised Learning, a model was created to predict the contact location. Furthermore, Stratified K-Fold Cross Validation (SKFCV) was used to divide the dataset. All these steps resulted in Neural Network with a test data accuracy higher than 80%. Regarding the real-time evaluation, a graphical interface was structured to demonstrate the predicted class and the corresponding probability. This research concluded that the method described has enormous potential to be used as a tool for service robots allowing enhanced human-robot interaction.

Highly Stretchable Additively Manufactured Capacitive Proximity and Tactile Sensors for Soft Robotic Systems

Soft robotics are considered one of the most promising approaches towards fully collaborative robotic devices. Soft robotic systems are intrinsically safe due to their compliant nature. Using additive fabrication for the development of soft capacitive sensors, enables high flexibility and individualization capabilities in terms of design and material properties. In this work, we outline the sensorization of stretchable capacitive sensors for proximity and tactile detection. This sensor will represent an essential component of a soft robotic finger in future work. While the functional principle has already been shown previously, here we explore the design space further and perform more in depth test of the influences of the strain on the tactile measurements. The capacitive pad’s sensitivity is evaluated by applying normal force on each sensor, where the applied force is ranged between 1N and 16N, with resultant capacitive change of the four tactile sensors between 1 pF and 60 pF. The capacitive pad’s proximity sensor is tested using five different materials, with proximity range of 20mm, with change in capacitance between 0.1 pF and 2.4 pF. An essential aspect of soft robotics is that also the sensor may be subject to substantial deformations. We demonstrate that our proposed sensor design can withstand large strains of more than 35% while the sensitivity towards sensing normal forces does not significantly change. This demonstrates that the proposed sensor design will be suitable for various soft robotics applications, where large deformations may occur.

Cognitive Impairment and Driving Skills in Youth After Concussion.

Abstract Concussions can impact cognitive processes necessary for driving. Young adults, a group who are more likely to engage in risky behaviors, have limited driving experience and a higher rate of motor vehicle collisions; they may be at higher risk for driving impairment after concussion. There are no clear guidelines for return-to-driving following a concussion. We sought to examine the simulated driving performance of young drivers after receiving medical care following a concussion, compared with a similar control population, to examine the association of driving performance with performance on neuropsychological tests. We evaluated 47 drivers, 16- to 25-year-old, within 3 weeks of sustaining a concussion and 50 drivers with similar characteristics who had not sustained concussions. Participants completed demographic questionnaires, the Sport Concussion Assessment Tool-5 (SCAT-5), and a brief set of neurocognitive tests, including the National Institutes of Health (NIH) Toolbox Cognition Battery and the Trail Making Test, and a simulated driving assessment. At various times during simulated driving, participants were asked to respond to tactile stimuli using the tactile detection response task (TDRT), a validated method of testing cognitive load during simulated driving. The concussion group reported significantly higher symptoms on the SCAT-5 than the comparison group. Performance on crystallized neurocognitive skills was similar between groups. Performance on fluid neurocognitive skills was significantly lower in the concussion than comparison group, although scores were in the normal range for both groups. Simulated driving was similar between groups, although there was a small but significant difference in variation in speed as well as TDRT miss rate, with worse performance by the concussion group. Symptom report on the SCAT-5 was significantly associated with TDRT miss rate. In addition, neurocognitive test scores significantly predicted TDRT reaction time and miss count with medium to large effect sizes. Results suggest that neurocognitive screening may be a useful tool for predicting capacity to return to drive. However, further research is needed to determine guidelines for how neuropsychological tests can be used to make return to driving recommendations and to evaluate effects of concussion on real world driving.

Influence of vibrotactile random noise on the smoothness of the grasp movement in patients with chemotherapy-induced peripheral neuropathy.

Patients with chemotherapy-induced peripheral neuropathy (CIPN) often suffer from sensorimotor dysfunction of the distal portion of the extremities (e.g., loss of somatosensory sensation, numbness/tingling, difficulty typing on a keyboard, or difficulty buttoning/unbuttoning a shirt). The present study aimed to reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor dysfunction in CIPN patients without exacerbating symptoms. Twenty-five patients with CIPN and 28 age-matched healthy adults participated in this study. To reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor function, participants were asked to perform a tactile detection task and a grasp movement task during random noise stimulation delivered to the volar and dorsal wrist. We set three intensity conditions of the vibrotactile random noise: 0, 60, and 120% of the sensory threshold (Noise 0%, Noise 60%, and Noise 120% conditions). In the tactile detection task, a Semmes-Weinstein monofilament was applied to the volar surface of the tip of the index finger using standard testing measures. In the grasp movement task, the distance between the thumb and index finger was recorded while the participant attempted to grasp a target object, and the smoothness of the grasp movement was quantified by calculating normalized jerk in each experimental condition. The experimental data were compared using two-way repeated-measures analyses of variance with two factors: experimental condition (Noise 0, 60, 120%) × group (Healthy controls, CIPN patients). The tactile detection threshold and the smoothness of the grasp movement were only improved in the Noise 60% condition without exacerbating numbness/tingling in CIPN patients and healthy controls. The current study suggested that the development of treatment devices using stochastic resonance can improve sensorimotor function for CIPN patients.

Ultrathin and highly breathable electronic tattoo for sensing multiple signals imperceptibly on the skin

The ideal epidermal electronics is desired to be comfortable to wear (e.g., imperceptible and breathable), simple to prepare without losing functionality. But real epidermal electronics always trade off its functionality, comfortability, and fabrication complexity. Herein, we present an ultrathin, breathable (20.5 mg/cm2h), multifunctional electronic tattoo (e-tattoo) that can be manufactured efficiently and cheaply. Ultrathin (0.15–11.09 µm) and porous thermoplastic polyurethane (TPU) film, obtained by combining simple rod-coating and polymer solution phase separation, provide excellent breathability for the devices. Silver nanowires (AgNWs) are sprayed on the porous film surface to form a strain-insensitive conductive layer. Based on porous films, a series of functional modules such as electrophysiological sensing, epidermal moisture sensing, touch sensing (with self-signal recognition), and pressure sensing (no interference with skin sensation) are described in the work. Experiments have shown that ultrathin and breathable e-tattoos have good conformability and can work imperceptibly on the skin for a long time. This e-tattoo with excellent comprehensive performance provides new ideas in health monitoring, human-computer interaction, and tactile information detection, and contributes to the development of next-generation epidermal electronic platforms.

Interhemispheric communication during haptic self-perception.

During the haptic exploration of a planar surface, slight resistances against the hand's movement are illusorily perceived as asperities (bumps) in the surface. If the surface being touched is one's own skin, an actual bump would also produce increased tactile pressure from the moving finger onto the skin. We investigated how kinaesthetic and tactile signals combine to produce haptic perceptions during self-touch. Participants performed two successive movements with the right hand. A haptic force-control robot applied resistances to both movements, and participants judged which movement was felt to contain the larger bump. An additional robot delivered simultaneous but task-irrelevant tactile stroking to the left forearm. These strokes contained either increased or decreased tactile pressure synchronized with the resistance-induced illusory bump encountered by the right hand. We found that the size of bumps perceived by the right hand was enhanced by an increase in left tactile pressure, but also by a decrease. Tactile event detection was thus transferred interhemispherically, but the sign of the tactile information was not respected. Randomizing (rather than blocking) the presentation order of left tactile stimuli abolished these interhemispheric enhancement effects. Thus, interhemispheric transfer during bimanual self-touch requires a stable model of temporally synchronized events, but does not require geometric consistency between hemispheric information, nor between tactile and kinaesthetic representations of a single common object.

Clinically Measuring Orofacial Somatosensation in a Cohort of Healthy Aging Adults.

Humans experience the world through sensations of touch, taste, smell, vision, and audition. Alterations in sensory acuity occur across the adult life span in all types of sensation. The purpose of this study was to describe possible differences in lip and tongue somatosensation (sense of pressure) for healthy older adults using clinically available measurement tools as compared with previously published data using the same protocol. A total of 33 healthy adults (ages 60-93 years; M = 70.5 years; 19 women) completed bilateral assessment of lip and tongue pressure detection and discrimination using two-point discrimination discs and Von Frey hair monofilaments. Participants reported basic health information and completed a pure-tone hearing threshold assessment within the same session. Descriptive results are presented for individual data points from healthy aging adults. Group data are compared with previously published data from a cohort of healthy young participants. Although there were no statistically significant differences between the two healthy groups, variations in standard deviations in older adults were observed. Two-point discrimination and tactile detection and discrimination using Von Frey hair monofilaments can be used to assess labial and lingual pressure detection and discrimination in healthy aging adults. While not reaching statistical significance, on average, older adults demonstrated increased threshold estimates compared with younger adults with increases in standard deviations up to 11.5 times larger than the younger cohort. Subtle differences in somatosensation across the ages may be important for future comparisons with clinical populations across the life span. These assessment techniques can be used with an aging population to complete objective orofacial somatosensory testing.

Somatosensory abnormalities after infection with SARS-CoV-2 - A prospective case-control study in children and adolescents.

BackgroundLong-term neurological complaints after SARS-CoV-2 infection occur in 4–66% of children and adolescents. Controlled studies on the integrity of the peripheral nerve system are scarce. Therefore, we examined the somatosensory function in children and adolescents after SARS-CoV-2 infection in a case-control study compared with age-matched individuals.Materials and MethodsEighty-one subjects after SARS-CoV-2 infection (n = 44 female, 11.4 ± 3.5 years, n = 75 SARS-CoV-2 seropositive, n = 6 PCR positive during infection and SARS-CoV-2 seronegative at the time point of study inclusion, n = 47 asymptomatic infection) were compared to 38 controls without SARS-CoV-2 infection (26 female, 10.3 ± 3.4 years, n = 15 with other infection within last 6 months). After standardised interviews and neurological examinations, large fibre (tactile and vibration detection thresholds) and small fibre (cold and warm detection thresholds, paradoxical heat sensation) functions were assessed on both feet following a validated protocol. After z-transformation of all values, all participants were compared to published reference values regarding the number of abnormal results. Additionally, the mean for all sensory parameters values of both study groups were compared to an ideal healthy population (with z-value 0 ± 1), as well as with each other, as previously described. Statistical analyses: t-test, Chi-squared test, and binominal test.FindingsNone of the controls, but 27 of the 81 patients (33%, p < 0.001) reported persistent complaints 2.7 ± 1.9 (0.8–8.5) months after SARS-CoV-2 infection, most often reduced exercise capacity (16%), fatigue (13%), pain (9%), or paraesthesia (6%). Reflex deficits or paresis were missing, but somatosensory profiles showed significantly increased detection thresholds for thermal (especially warm) and vibration stimuli compared to controls. Approximately 36% of the patients after SARS-CoV-2, but none of the controls revealed an abnormal sensory loss in at least one parameter (p < 0.01). Sensory loss was characterised in 26% by large and 12% by small fibre dysfunction, the latter appearing more frequently in children with prior symptomatic SARS-CoV-2 infection. Myalgia/paraesthesia was indicative of somatosensory dysfunction. In all eight re-examined children, the nerve function recovered after 2–4 months.InterpretationThis study provides evidence that in a subgroup of children and adolescents previously infected with SARS-CoV-2, regardless of their complaints, the function of large or small nerve fibres is presumably reversibly impaired.

The influence of reduced foot dorsum cutaneous sensitivity on the vestibular control of balance.

Foot sole cooling increases vestibular-evoked balance responses, but less is known about foot dorsum temperature alterations. The purpose was to determine whether decreasing cutaneous receptor sensitivity via foot dorsum cooling modulates the vestibular control of balance. Eighteen participants (9 males; 9 females) stood quietly on a force plate with feet together, eyes closed, and head rotated leftward during 4, 90-s trials (2 control; 2 cooled) of continuous electrical vestibular stimulation (EVS). Icepacks placed on the dorsum of both feet for 15min induced cooling and remained throughout the EVS trials. Monofilament testing was performed at multiple locations before and after cooling to determine tactile detection thresholds. T-type thermocouples monitored skin temperature over the tibialis anterior, soleus, foot dorsum and arch of the right leg. Vestibular-evoked balance responses were characterized using time (cumulant density) and frequency (coherence and gain) domain analyses to determine the relationship between the EVS input and motor output (anteroposterior force-AP force; right medial gastrocnemius electromyography-MG EMG). Skin temperature of the foot dorsum and arch decreased ~ 70 and 15%, respectively during cooling (p < 0.05), but was unaltered at other locations (p ≥ 0.10). Detection thresholds for the foot dorsum increased following cooling (p < 0.05). Surprisingly, cooling reduced EVS-AP force and EVS-MG EMG coherence and gain at multiple frequencies, and peak-to-peak amplitude compared to control (p < 0.05). Our results indicate that vestibular-driven balance responses are reduced following foot dorsum cooling, likely owing to alterations in cutaneous mechanoreceptor sensitivity and subsequent alterations in the transformation of vestibular cues for balance control.

A Novel Tactile Sensor for Slip Detection Based on Relative Angular Velocity

Object slippage should be prevented as one of the major challenges in robotic manipulation. Applying insufficient grasp force leads to the object slip, whereas a large predetermined grasp force can damage sensitive and fragile objects. The ability to detect slippage in real-time implementations provides required feedback for grasp force regulation, which allows the hand (gripper) to reach the appropriate grasp force and prevent object slip. Predominantly during the slip sensation, high-frequency vibrations are generated due to the relative motion between the object and the fingers. In the present work, a novel tactile slip detection sensor was developed based on the effects of skin vibrations resulting from the slip and by measuring the relative angular velocity between the skin and the rigid parts of the finger. Substantial experimental studies revealed the proposed method can detect slippage events with a 100% success rate and low latency, which reveals merits of the proposed method and the fabricated sensor. Also, the sensor arrangement is designed with an emphasis on minimizing the noise resulting from the actuation motions and vibrations, and increasing the sensitivity to the slippage events.

The vision of haptics tunes the somatosensory threshold

The interaction between different sensory modalities represents a crucial issue in the neuroscience of consciousness: when the processing of one modality is deficient, the concomitant presentation of stimuli of other spared modalities may sustain the restoration of the damaged sensory functions. In this regard, visual enhancement of touch may represent a viable tool in rehabilitating tactile disorders, yet the specific visual features mostly modulating the somatosensory experience remain unsettled.In this study, healthy subjects underwent a tactile detection task during the observation of videos displaying different contents, including static gratings, meaningless motions and natural or point-lights reach-to-grasp-and-manipulate actions. Concurrently, near-threshold stimuli were delivered to the median nerve at different time-points. The subjective report was collected after each trial; the sensory detection rate was computed and compared across video conditions.Our results indicate that the specific presence of haptic contents (i.e., the vision of manipulation), either fully displayed or implied by point-lights, magnifies tactile sensitivity. The notion that such stimuli prompt a conscious tactile experience opens to novel rehabilitation approaches for tactile consciousness disorders.

A Multidimensional Investigation of Sensory Processing in Autism: Parent- and Self-Report Questionnaires, Psychophysical Thresholds, and Event-Related Potentials in the Auditory and Somatosensory Modalities.

BackgroundReconciling results obtained using different types of sensory measures is a challenge for autism sensory research. The present study used questionnaire, psychophysical, and neurophysiological measures to characterize autistic sensory processing in different measurement modalities.MethodsParticipants were 46 autistic and 21 typically developing 11- to 14-year-olds. Participants and their caregivers completed questionnaires regarding sensory experiences and behaviors. Auditory and somatosensory event-related potentials (ERPs) were recorded as part of a multisensory ERP task. Auditory detection, tactile static detection, and tactile spatial resolution psychophysical thresholds were measured.ResultsSensory questionnaires strongly differentiated between autistic and typically developing individuals, while little evidence of group differences was observed in psychophysical thresholds. Crucially, the different types of measures (neurophysiological, psychophysical, questionnaire) appeared to be largely independent of one another. However, we unexpectedly found autistic participants with larger auditory Tb ERP amplitudes had reduced hearing acuity, even though all participants had hearing acuity in the non-clinical range.LimitationsThe autistic and typically developing groups were not matched on cognitive ability, although this limitation does not affect our main analyses regarding convergence of measures within autism.ConclusionOverall, based on these results, measures in different sensory modalities appear to capture distinct aspects of sensory processing in autism, with relatively limited convergence between questionnaires and laboratory-based tasks. Generally, this might reflect the reality that laboratory tasks are often carried out in controlled environments without background stimuli to compete for attention, a context which may not closely resemble the busier and more complex environments in which autistic people’s atypical sensory experiences commonly occur. Sensory questionnaires and more naturalistic laboratory tasks may be better suited to explore autistic people’s real-world sensory challenges. Further research is needed to replicate and investigate the drivers of the unexpected association we observed between auditory Tb ERP amplitudes and hearing acuity, which could represent an important confound for ERP researchers to consider in their studies.

Investigation of Three Potential Stress Inducement Tasks During On-Road Driving

A driving study was performed to induce stress with 24 participants performing different inducement tasks (n-back task, Sing-a-Song Stress Test and noise exposure). Both performance-based measures (Tactile Detection Response Task) as well as subjective measures were recorded to assess the driver state. Subjective ratings indicate that stress was most successfully induced on a group level with the n-back task with high inter-individual variation. The average response times doubled during the n-back task for a simultaneously performed tactile detection response task compared to baseline response times. Sympathetic nervous activation resulting in the increase of heart rate, respiration rate and decrease in heart rate variability (RMSSD) was found as a physiological reaction on stress-inducing secondary tasks. The most prominent physiological responses were found during the modified Sing-a-Song Stress Test. Subjective ratings on the perceived stress level and physiological response rarely correlated. This study provided reference data for driver state algorithm development in the EU-funded project ADAS&ME.

Reconfigurable Fiber Triboelectric Nanogenerator for Self-Powered Defect Detection.

With the extensive applications of portable, wearable, and stretchable electronics, the fiber triboelectric nanogenerator (TENG) has been developed particularly and rapidly. However, variable stiffness or even switchable stiffness for the fiber TENG is also urgently needed in some specific service conditions. Here, the functional, reconfigurable fiber TENG is presented for harvesting mechanical energy and self-powered sensors. It is mainly composed of soft tubes with filled low-melting-point alloy (LMPA), conductive wire, and electrically heated wire. Under an input frequency of 3 Hz, this fiber TENG produces a maximum peak power density of 348.5 μW/m. Due to its excellent reconfigurable characteristics, it can be switched back and forth in many different application situations. It can be intelligently used not only as a self-powered tactile and mechanical sensor but also as a self-powered splint for postdisaster relief work. Besides, the cracking detection of a gear and a lead screw is also realized using this fiber TENG. This work strongly promotes the application of variable stiffness LMPAs in the TENG, especially for the reconfigurable fiber TENG. It also promotes the potential self-powered applications of the TENG in the fields of sensors and detection, such as mechanical flaw detection and self-powered tactile detection.

Comparison of piezoelectric responses of flexible tactile sensors based on hydrothermally-grown ZnO nanorods on ZnO seed layers with different thicknesses

One peculiar property of ZnO nanorods (NRs) is their piezoelectricity, which opens up a wealth of possibilities in the fields of piezoelectric electronics and piezoelectric optoelectronics, such as pressure sensors, actuators, energy-capture and energy-storage devices. For further clarifying the relation between the piezoelectric properties and structural morphology of ZnO NRs, the effect of their aspect ratio on piezoelectric response was analyzed by simulation method. A piezoelectric tactile sensor with ZnO NRs as a sensitive layer hydrothermally grown on a sputtered ZnO seed layer (SL) was fabricated on a polydimethylsiloxane (PDMS) substrate. The effects of the SL thickness on the structural properties and morphology of ZnO NRs were investigated, and a comparative study on the piezoelectric sensing of the tactile sensors with different SL thicknesses was done. The results show that the ZnO SL thickness has a clear influence on the structural morphology of the ZnO NRs and the sensitivity of the ZnO-NRs-based sensor, and the sensor with a SL thickness of 80 nm has a maximum sensitivity of 524.5 mV/N due to the high aspect ratio. Moreover, the sensors have a good linear response to external pressure within the range of less than 1 N, and so exhibit excellent application prospects in tactile perception and detection of weak dynamic force.

All-textile sensors for boxing punch force and velocity detection

All-textile-based wearable sensors attract immense interest as a big data collection platform for human motion detection, providing multifunctionality, high sensitivity, and excellent wearing comfort for sports applications. Herein, we demonstrate a flexible bimodal all-textile sensor design with touchless and tactile detection capability via a scalable and cost-effective fabrication route for sensitive motion detection. The slight changes in the surrounding microenvironment such as pressure, and proximity distance can be continuously and simultaneously detected by the bimodal all-textile sensor based on a 3D hierarchical spacer fabric dielectric layer and nickel fabric electrode. The bimodal all-textile sensor exhibits a superior tactile sensing sensitivity (0.33 kPa−1), an ultralow detection limit (0.25 Pa), excellent touchless performance (detection distance of 20 cm, maximum relative capacitance changes of 20%), and comfortable textile properties, such as excellent air breathability (448.77 mm/s)) and moisture permeability (147.11 g/(m2 h)), mechanical stability (> 10,000 cycles), and low manufacturing cost (6.5 $/m2). Our bimodal all-textile sensor with high performance and cost-effectiveness presents substantial advantages for smart textiles and garments used in the intelligent digitalization of physical combat sports training applications.

Effect of ageing and tooth loss on sensory function of alveolar mucosa.

Maintaining quality of life of elderly denture wearers is one of the most crucial tasks for dentists in the super-aged society. Although external mechanical load on removable dentures has been investigated to minimise a risk of soreness caused by dentures, sensory perception of the alveolar mucosa remains obscure. This study aimed to investigate effect of ageing and tooth loss in sensory function on the alveolar mucosa for deep understanding of the characteristics of pain sensitivity in edentulous individuals. Eighteen edentulous participants (ED), as well as 18 age-matched dentate participants (EC) and 18 young dentate participants (YC), participated in this study. Tactile detection threshold (TDT) and pain threshold (PT) were measured with von Frey filaments (0.125-512mN). Mechanical pain sensitivity (MPS) after a 2-sec application of 1kg palpation was assessed with a 0-50-100Numerical Rating Scale (NRS) (0: no pain, 50: slight pain and 100: the worst pain imaginable). Furthermore, entropy scores of TDT, PT and NRS on MPS were calculated. In both maxilla and mandible, EC showed significantly higher TDT and PT, compared with YC, whereas ED showed significantly lower TDT and PT, compared with EC. NRS on MPS in ED was significantly higher than that in EC. The entropy scores of all the outcome parameters showed no significant difference between groups. Both ageing and tooth loss can alter tactile and pain perception in the oral mucosa. This suggests that it might be beneficial to assess sensory function of the alveolar mucosa in edentulous patients clinically in prior to denture fabrication.