Somatosensory Research Articles

Electret mechano-sensor array integrated with tribopotential-modulated thin film transistors for precise spatiotemporal pressure perception

Spatiotemporal pressure perception is a key function of electronic skins. Electret mechano-sensors, as active sensors for E-skins, have garnered significant interest, with outstanding sensing performance in dynamic pressure measurement. However, their high output impedance poses a challenge in accurately and simply measuring low-frequency or static pressure distribution. Herein, we proposed an electret mechano-sensor array, in which each sensing cell is based on an electret sensor integrated with an IGZO TFT. The high input impedance of the TFT facilitates the sensor signal readout and enables the measurement of static pressure. The super-linear amplification feature of the TFTs improves the sensitivity and linearity of the sensors. An IGZO TFT layer with the lower electrodes of the electret sensor was fabricated through microfabrication process and assembled with a pre-charged electret film to achieve a mechano-sensor array with a high density. The fabricated TFT-integrated electret mechano-sensor array has achieved pattern detection and spatial tactile perception. Moreover, the sensor array can record spatiotemporal static pressure and arterial pulse waves simultaneously, exhibiting high resolution in detecting subtle changes and potentially offering various physiological information regarding the cardiovascular system. This work demonstrated that the proposed mechano-sensor array has capabilities for broad-scale pressure distribution detection in healthcare monitoring and human-computer interaction.

Association Between Television Viewing and Sensory Reactivity in Childhood: The Cross-Sectional InProS Study

BackgroundCurrent evidence suggests a potential detrimental effect of increased television viewing on children's health, including sensory processing issues. Therefore, this study examined the association between television viewing time and atypical sensory reactivity (SR) in children aged from three to seven years. MethodsWe evaluated data from the InProS cross-sectional study (n = 545). Daily television viewing was categorized into tertiles: ≤1.5, 1.5 to 2.5, and ≥2.5 hours. SR was evaluated using the Short Sensory Profile (SSP). Children with atypical SR were those with a global SSP score below 155, 30 for tactile sensitivity, 15 for taste/olfactory sensitivity, 13 for movement sensitivity, 27 for under-responsive/seeks sensation, 23 for auditory filtering, 26 for low energy/weak, and 19 for visual/auditory sensitivity. We used multiple Poisson regression models with robust variance to explore associations. ResultsAfter adjusting for covariates, children who watched television 1.5 to 2.5 and ≥2.5 hours/day showed a higher prevalence of atypical global SR (prevalence ratio [PR]: 1.54; 95% confidence interval [CI]: 1.03 to 2.30; PR: 1.81; 95% CI: 1.19 to 2.76, respectively) and auditory filtering (PR: 1.50; 95% CI: 1.15 to 1.96; PR: 1.36; 95% CI: 1.01 to 1.83, respectively), compared with children who watched ≤1.5 hours/day. In addition, watching television ≥2.5 hours/day, compared with watching ≤1.5 hours/day, was associated with having atypical SR in movement sensitivity (PR: 1.73; 95% CI: 1.06 to 2.83), under-responsive/seeks sensation (PR: 1.31; 95% CI: 1.02 to1.69), and low energy/weak (PR: 2.02; 95% CI: 1.01 to 4.06). ConclusionsThe findings showed that television viewing ≥1.5 hours/day was associated with a higher prevalence of atypical SR in childhood. However, further longitudinal studies are required to confirm these results.

Jun modulates endoplasmic reticulum stress-associated ferroptosis in dorsal root ganglia neurons during neuropathic pain by regulating Timp1

Neuropathic pain (NP) is a complex disorder caused by lesions or diseases affecting the somatosensory nervous system, severely impacting patients' quality of life. Recent studies suggest ferroptosis may be involved in NP induction, but its precise mechanisms remain unclear. We used GO and KEGG pathway enrichment analyses to functionally annotate ferroptosis-related differentially expressed genes (FRDs). Through STRING and the maximum cluster centrality (MCC) algorithm, we identified five hub FRDs (Jun, Timp1, Egfr, Cdkn1a, Cdkn2a). Single-cell analysis revealed significant expression of Jun and Timp1 in neurons. Our study confirmed the association between ferroptosis and endoplasmic reticulum stress (ERS) in NP and validated changes in hub FRD expression across various NP animal models. In vitro experiments demonstrated that Jun regulates neuronal ferroptosis and ERS, particularly by modulating Timp1 expression. Transcription factor prediction and JASPAR binding site analysis elucidated the regulatory network involving Jun. ROC curve analysis of external datasets highlighted the diagnostic potential of hub FRDs and ERS-related differentially expressed genes (ERSRDs) in NP. Using the Comparative Toxicogenomics Database (CTD), we identified estradiol (E2) as a potential therapeutic drug targeting hub FRDs and ERSRDs. Molecular docking predicted its binding sites with Jun and Timp1, and in vivo experiments confirmed that E2 alleviated NP and reversed the expression of Jun and Timp1. This study underscores the crucial role of Jun and Timp1 in the interplay between ferroptosis and ERS, offering new insights and promising avenues for NP treatment.

The effect of live-performed music therapy with physical contact in preterm infants on parental perceived stress and salivary cortisol levels.

Parents of preterm infants face a stressful life event which might have long term impact on the parent-child relation as well as on the infant's cognitive and socio-emotional development. Both music therapy (MT) and physical contact (PC) are stress-reducing interventions for parents and preterm infants on the neonatal intensive care unit (NICU). Meanwhile, especially close PC is considered as standard care (SC) in most NICUs. However, the effect of live performed MT with PC on parental perceived stress and cortisol levels has barely been investigated. We hypothesized that MT with PC leads to reduced stress levels and lower salivary cortisol concentrations compared to SC in parents of preterm infants during the first 4 weeks after birth. Randomized-controlled trial enrolling the parents of 99 preterm infants (MT n = 50, SC n = 49 infants). The infants received either MT with PC or SC only. Perceived stress was measured with the perceived stress questionnaire 20 (PSQ-20) after birth and 4 weeks later. Salivary cortisol levels were obtained and measured weekly after birth for 4 weeks. Forty-two mothers and eight fathers of the intervention group (MT with PC) as well as n = 43 mothers and n = 6 fathers of the control group (SC) were enrolled. For the intervention group, salivary cortisol was reduced 4 weeks after birth [mothers 5.5 nmol/l (confidence interval (CI) 3.6-7.5); fathers 8.3 (CI 7.2-9.4)] compared to the control group [mothers 10.3 nmol/l (CI 5.4-15.3); fathers 14.8 (CI 8.9-20.7)]. Overall perceived stress scores decreased in the intervention group (mothers -17.6; fathers -12.6) and increased in the control group (mothers +6.1; fathers +21.4) over 4 weeks. Live-performed MT with PC in preterm infants might be an effective, non-invasive intervention to reduce parental stress and cortisol levels. Future studies should investigate the long-term effects of this intervention on the parent-infant relation as well as on the infants' cognitive and socio-emotional development. https://drks.de/search/en/trial/DRKS00025755 identifier [DRKS00025755].

Multiplexed Piezoelectric Electronic Skin with Haptic Feedback for Upper Limb Prosthesis

AbstractUpper limb amputation severely impairs tactile perception, limiting daily activities. Developing a near‐natural replacement with prosthetic devices requires improving user sensory experiences during object interactions. The ideal upper limb prosthesis should provide real‐time sensory feedback, mirroring natural experiences. Current prostheses struggle with providing adequate tactile feedback due to sensory limitations. Inspired by the sensory properties of skin, we present a micro‐fabricated, multiplexed electronic skin (e‐skin) with actuators for sensory feedback in upper limb amputation. The piezoelectric‐capacitive sensor array detects static pressure, temperature, vibration, and texture, with integrated actuators stimulating the skin to provide real‐time feedback. The sensors integrate with actuators via readout electronics, making the system standalone and easy to use. The flexible, compact sensor array design (two pixels within a 1 cm² footprint) detects a wide range of pressure (0.5–10 kPa), temperature (22–60 °C), vibration (35–100 Hz), and texture (2.5–45 Hz), suitable for daily use. The e‐skin, attached to a prosthetic finger, is tested for feasibility on human volunteers with wrist‐mounted actuators. Statistics are used to quantitatively assess system performance. The integration of multiplexed sensors and actuators enhances tactile feedback, improving the quality of life for people with upper limb amputations.

Together, alone: Personal experiences of virtual funeral attendance during the COVID-19 global pandemic

The COVID-19 pandemic caused profound distortions in how deaths were marked by those left to mourn their passing. Public health restrictions prohibited gatherings of friends and families for traditional funerals, causing an upsurge in reliance on virtual alternatives. The aim of this study was to explore the experiences of individuals attending virtual funerals following a death of any cause, including reasons for choosing virtual attendance, perceived differences relative to in person attendance, and the extent to which mourning practices were accommodated. Between May 2021 and June 2022, we identified 57 participants with virtual funeral attendance experience. They identified many shortcomings of virtual funerals, captured under themes including, socialization, community support, sharing food, physical contact, consoling the bereaved, sharing memories, and connection. There were features of virtual funerals that participants appreciated, summarized by themes including, accessibility, taking part or marking the event, closure, technological advantages and privacy. Despite a sense that virtual funerals provided an opportunity to grieve “together, alone,” most conceded it was better than not being able to take part at all. This study provides detailed information about participating in virtual funerals, identifying features of this experience that should be examined to determine how those may influence grieving processes and bereavement outcomes.

Flexible and Transparent Electrovibration-Based Haptic Display with Low Driving Voltage.

Electrovibration haptic technology, which provides tactile feedback to users by swiping the surface with a finger via electroadhesion, shows promise as a haptic feedback platform for displays owing to its simple structure, ease of integration with existing displays, and simple driving mechanism. However, without electrical grounding on a user's body, the frequent requirement of a high driving voltage near 50 V limits the use of electrovibration haptic technology in practical display applications. This study introduces materials and fabrication strategies that considerably reduce the driving voltage. We used a transparent poly(vinylidene fluoride) (PVDF) thin film deposited on transparent conductive polymers through a simple spin-coating process, thereby enabling easy integration with existing display technologies. The high dielectric constant characteristics of PVDF enabled the production of tactile cues at low voltages (approximately 15 V), which are within the safety limits of common electronics. We verified the feasibility of our electrovibration haptic feedback system on the basis of the absolute threshold voltage through two-alternative forced choice psychological tests. The results revealed that the PVDF dielectric layer exhibited a relatively lower absolute threshold than commonly used polymer films, which possess a relatively lower dielectric constant. To validate the tactile attributes, a Likert five-point scale survey was conducted, considering flat, concave, and convex curvatures. The results indicated that our haptic device can render diverse surface textures, such as "hairy" and "groovy", on the fingertips through the control of applied pulse width modulated voltage signals.

Ion channels of cold transduction and transmission.

Thermosensation requires the activation of a unique collection of ion channels and receptors that work in concert to transmit thermal information. It is widely accepted that transient receptor potential melastatin 8 (TRPM8) activation is required for normal cold sensing; however, recent studies have illuminated major roles for other ion channels in this important somatic sensation. In addition to TRPM8, other TRP channels have been reported to contribute to cold transduction mechanisms in diverse sensory neuron populations, with both leak- and voltage-gated channels being identified for their role in the transmission of cold signals. Whether the same channels that contribute to physiological cold sensing also mediate noxious cold signaling remains unclear; however, recent work has found a conserved role for the kainite receptor, GluK2, in noxious cold sensing across species. Additionally, cold-sensing neurons likely engage in functional crosstalk with nociceptors to give rise to cold pain. This Review will provide an update on our understanding of the relationship between various ion channels in the transduction and transmission of cold and highlight areas where further investigation is required.

Posture Estimation Model Combined With Machine Learning Estimates the Radial Abduction Angle of the Thumb With High Accuracy.

The thumb function is complex, and accurate evaluation through images or videos is difficult. Pose estimation, a technology that uses artificial intelligence (AI) to estimate skeletal detection of the body, is gaining popularity.In this study, we combined the pose estimation library MediaPipe-Hands and five machine learning (ML) models to predict the radial abduction angle of the thumb.Radial abduction movements of 20 hands from 10 healthy volunteers were captured on video and processed into 5,000 images. Angle measurements by goniometer were used as true values to evaluate the angle reliability of the MediaPipe-Hands and the angle reliability of the MediaPipe-Hands combined with ML. The correlation coefficient (CC) between the angle measured by goniometry and the angle calculated by MediaPipe-Hands was 0.84. In contrast, applying ML to MediaPipe-Hands resulted in models with improved accuracy, and all models showed high CCs (0.94-099) with angle measurements taken by goniometry. The ML model also predicted the abduction angles when the camera was taken from three different angles. In visualizing the features that the AI deemed important, the ML model predicted the abduction angle by focusing on the tip distance between the thumb and index finger along with the angle of the metacarpophalangeal joint between the thumb and middle finger. These results enable angle estimation even without frontal imaging with a camera, and expansion of this system may lead to real-time functional assessment in telemedicine and rehabilitation without the need for physical contact.

Light-Controlled Magnetic Properties: An Energy-Efficient Opto-Mechanical Control over Magnetic Films by Liquid Crystalline Networks.

Magnetostrictive materials are essential components in sensors, actuators, and energy-storage devices due to their ability to convert mechanical stress into changes in magnetic properties and vice-versa. However, their operation typically requires physical contact to apply stress or relies on magnetic field sources to control magnetic properties. This poses significant limitations to devices miniaturization and their integration into contactless technologies. This work reports on an approach that overcomes these limitations by using light to transfer mechanical stress to a magnetostrictive device, thereby achieving non-contact and reversible opto-mechanical control of its magnetic and electrical properties. The proposed solution combines a magnetostrictive Fe70Ga30 thin film with a photo-responsive Liquid Crystalline Network (LCN). Magnetic properties are modulated by changing the light wavelength and illumination time. Remarkably, the stable shape change of the LCN induced by ultraviolet (UV) light leads to the retention of magnetic properties even after the light is switched off, resulting in a magnetic memory effect with an energy consumption advantage over the use of conventional magnetic field applicators. The memory effect is erased by visible light, which releases the mechanical stress in the photoresponsive layer. Therefore, this new composite material creates a fully reconfigurable magnetic system controlled by light.

Development of linear bearing equipment for modal testing of low-frequency weakly damped spacecraft structures

This article presents the results of a study of the bearing capacity and dissipative properties of an aerostatic linear bearing developed at JSC RESHETNEV for modal testing of complex structures. When selecting equipment for modal testing, the main condition is the requirement to minimize the distortions introduced into the determined dynamic characteristics: frequencies of natural vibration modes, the vibration modes themselves, as well as modal masses and damping coefficients. In other words, all equipment used for ground-based modal testing should ideally have zero added mass, stiffness and friction. The main systems containing elements that create dissipative forces that affect the determination of damping coefficients are systems for weight compensation and vibration excitation on natural modes. The weight compensation system usually contains either elastic elements or a system of guides with rolling or sliding bearings. If the former bring additional rigidity and mass to the test object, the latter bring mass and friction (dry or viscous), which increases the error in determining the dynamic characteristics. The excitation of vibrations on natural modes, in most cases, is carried out by electrodynamic vibrators consisting of a magnetization coil (or permanent magnet) and a movable coil moving in a magnetic gap. The movable coil is oriented in the magnetic gap using a special system containing either elastic elements or a linear guide bearing. Vibrators with elastic coil suspension elements cannot be used for modal tests of extended structures with low rigidity. The problem of creating an ideal bearing to replace classic linear (sliding or roller) ones arose during preparation for modal tests of the wing of a solar battery of a spacecraft (SC). Aerostatic bearings (supports) have virtually zero friction and sufficient load-bearing capacity, in which compressed air acts as a lubricant, eliminating physical contacts of the interacting surfaces. To confirm the possibility of using aerostatic bearings in equipment for conducting modal tests of extended structures with low frequencies of natural oscillations, comparative tests of a roller and aerostatic bearing were carried out. During the tests, optimal air flow parameters (nozzle diameter, operating pressure and gap) were selected, which ensure the required load-bearing capacity for radial forces and torques (bending and torsion). A comparative assessment of dissipative properties was carried out when measuring the attenuation parameters of single-mass harmonic oscillators, which include aerostatic and roller linear bearings. With a nozzle diameter of 0.6 mm, a working gap of 40 μm and a bearing input pressure of 1.0 bar, the logarithmic decrement of oscillations of the harmonic oscillator with an aerostatic bearing was 0.084, which is more than 28 times lower than the logarithmic decrement of oscillations of an oscillator with a roller bearing. The conducted studies confirmed the possibility of using the developed aerostatic bearing in test systems used in modal tests of large-sized transformable spacecraft structures.

Negative Effect of the Calendering Process on the Interphase Formation and Electrochemical Behavior of Reduced Graphene Oxide Electrodes.

Many studies on electrode material development for rechargeable batteries have focused on improving the intrinsic physicochemical and electrochemical properties of active materials, but the electrochemical performances of batteries are exhibited by the overall electrode unit consisting of active materials, conductive additives, and a binder. Additionally, the electrodes have undergone an essential calendering process to enhance the physical contact between those components. Therefore, the electrochemical behavior and performance of a cell should be analyzed at the electrode level, as the inherent properties of active materials might be changed in electrode preparation, including the calendaring process and real-operating environments. In this study, we aimed to understand the electrochemical properties of the reduced graphene oxide (RGO)-containing electrodes rather than the RGO-active materials by studying the changes in the RGO electrode before and after the calendering process. Specifically, the study investigates the effect of the calendering process on the electrochemically active interphase formation and electrochemical properties of the RGO electrode. We found that the calendering process deteriorates the electrochemical properties of RGO electrodes by impeding enough electrolyte wetting, limiting the formation of thin and stable solid-electrolyte interphase, and leaving unreacted RGO sheets. Additional experiments with carbon-coated silicon/RGO composite electrodes demonstrate that after the calendering process, the sequential participation of Si/C particles in the electrochemical reaction resulted in much more severe capacity degradation over repeated cycling processes. The studies suggest that fine-controlling the number of RGO sheets and maintaining enough distance between those sheets even after the calendering process are required for the utilization of RGO in rechargeable batteries.

Comprehensive evaluation on wearing and hearing comfort of over-ear headphones based on adjustable clamping force

Headphones are wearable devices that directly contact the human body. Ergonomics focuses on the wearing comfort associated with clamping force, which is closely related to the user's tactile perception. Additionally, as auditory input terminal devices, headphones should also encompass the aspect of hearing comfort. Theoretically, slight and uneven clamping force may cause noise exposure, subsequently influencing hearing comfort. Conversely, an overloaded clamping force, while aiming to improve hearing conditions, may introduce discomfort for the wearer. Therefore, the current work concerns the interplay between wearing and hearing comfort. In this study, four loudspeakers placed around a listener in a sound insulation room render a stable noise environment. A dynamometer mounted on a horizontal track radially supplies specific clamping force on the two earmuffs of an over-ear headphone worn by the listener. Simultaneously, a comfort questionnaire was employed to investigate users' subjective perceptions of wearing and hearing comfort under various clamping forces. These results could provide a valuable reference for the design and evaluation of over-ear headphones.

Immediate effects of electronic stimulation to the plantar foot on foot function and postural stability during landing.

Sports injuries often occur during landing, necessitating postural stability for injury prevention. Electrical stimulation of the plantar foot induces activities of the intrinsic foot muscles and improves somatosensory and postural stability during landing. However, this effect remains unclear. Therefore, the aim of this study was to investigate the immediate effects of electrical stimulation on the activities of the intrinsic foot muscles, plantar somatosensory system, and postural stability during landing. Twenty-two college athletes were divided into an electrical stimulation group and a control group. Electrical stimulation was applied to the plantar foot using a commercial device. The toe function and plantar tactile sensations were evaluated. The activities of the intrinsic muscles and the parameters of the ground reaction force were measured and calculated. We compared pre- and postintervention outcomes. In the electrical stimulation group, two subjects showed improvement in toe function, and plantar tactile sensation improved significantly postintervention. The control group exhibited no significant change in plantar tactile sensation. A significant interaction was observed in anteroposterior postural stability during landing, notably improving in the electrical stimulation group. Electrical stimulation of the plantar foot immediately improved toe function, plantar tactile sensation, and postural stability during landing. Such stimulation would be beneficial in preventing sports injuries.

Clinical Applications and Future Translation of Somatosensory Neuroprostheses.

Somatosensory neuroprostheses restore, replace, or enhance tactile and proprioceptive feedback for people with sensory impairments due to neurological disorders or injury. Somatosensory neuroprostheses typically couple sensor inputs from a wearable device, prosthesis, robotic device, or virtual reality system with electrical stimulation applied to the somatosensory nervous system via noninvasive or implanted interfaces. While prior research has mainly focused on technology development and proof-of-concept studies, recent acceleration of clinical studies in this area demonstrates the translational potential of somatosensory neuroprosthetic systems. In this review, we provide an overview of neurostimulation approaches currently undergoing human testing and summarize recent clinical findings on the perceptual, functional, and psychological impact of somatosensory neuroprostheses. We also cover current work toward the development of advanced stimulation paradigms to produce more natural and informative sensory feedback. Finally, we provide our perspective on the remaining challenges that need to be addressed prior to translation of somatosensory neuroprostheses.

“Where’s my baby?” A feminist phenomenological study of women experiencing preventable separation from their baby at caesarean birth

ProblemSeparating women and babies immediately after birth contributes to poor birth experience and reduced satisfaction. BackgroundA negative birth experience can impact a woman’s transition to motherhood and emotional well-being beyond the newborn period. Separating women from their baby at birth is known to reduce birth satisfaction and is more likely to happen at caesarean section births. QuestionWhat is the experience of women who are separated from their baby after caesarean section birth without medical necessity? MethodsUnstructured, in-depth phenomenological interviews were conducted with fifteen women who had been separated from their well-baby at caesarean section birth. Data was analysed using a Modified van Kaam approach. A novel feminist phenomenological framework with two birthing theories was used to explore the experience of the participants. FindingsFour major themes emerged – Disconnection, Emotional Turmoil, Influence, and Insight. These demonstrated significant trauma that both the separation and perinatal care created. DiscussionThe participants recognised their vulnerability and the lack of power and control they had over themselves and their baby, which was seemingly not acknowledged. Provider and hospital needs were valued above those of the women. ConclusionWoman-centred care was not evident in the treatment of these women despite the attendance of a midwife at each birth. This research challenges midwives and other health care providers to support and advocate for those birthing by caesarean section to return power and control and support them to remain in close physical contact with their baby immediately after birth.

The effect of female breast surface area on skin stiffness and tactile sensitivity at rest and following exercise in the heat.

Female development includes significant morphological changes across the breast. Yet, whether differences in breast surface area (BrSA) modify breast skin stiffness and tactile sensitivity at rest and after exercise in the heat remain unclear. We investigated the relationship between BrSA and skin stiffness and tactile sensitivity in 20 young to middle-aged women (27±8years of age) of varying breast sizes (BrSA range: 147-502cm2) at rest and after a submaximal run in a warm climatic chamber (32 ± 53%±1.7% relative humidity). Skin stiffness above and below the nipple and tactile sensitivity from the nipple down were measured. Associations between BrSA and both skin stiffness and tactile sensitivity at rest were determined via correlation analyses. Effects of exercise and test site were assessed by a two-way ANOVA. Skin stiffness was positively correlated with BrSA 3cm above the areola edge (r=0.61, P=0.005) and at the superior areola border (r=0.54, P=0.016), but not below the nipple (P>0.05). The area 3cm below the areola was also significantly stiffer than all other test sites (P<0.043). Tactile sensitivity did not vary with BrSA (P>0.09), but it varied across the breast (i.e., the area 3cm below the areola was more sensitive than the inferior areola edge; P=0.018). Skin stiffness and tactile sensitivity across the breast decreased after exercise by ∼37% (P<0.001) and ∼45% (P=0.008), respectively. These findings expand our fundamental understanding of the mechanosensory properties of the female breast, and they could help to inform sportswear innovation to better meet the support needs of women of different breast sizes at rest and following exercise.

Contributions of tactile information to the sense of agency and its metacognitive representations.

Despite the ubiquitous presence of tactile information in our daily activities, studies of how we experience agency of our actions have rarely relied on manipulated visuo-tactile feedback. Instead, what is often manipulated are the distal (and arbitrarily associated) consequences of our actions. The few studies that did investigate whether tactile information contributes to the experience of agency have been limited to the binary assessment of tactile feedback about the outcome of an action being present or absent. Here, we went beyond the coarse comparison of agency with versus without tactile feedback and introduced instead an experimental manipulation where we could control the amount of mismatch between predictions and observations. Participants (N = 40) reached with their right hand toward a ridged plate with a specific orientation and saw online feedback that could match or differ from their action in one of three ways: the physical plate's orientation, the action's timing, or the hand's position in space. Absolute subjective ratings revealed that an increased mismatch in tactile information led to a diminished sense of agency, similar to what has been reported for spatial and temporal mismatches. Further, estimations of metacognitive efficiency revealed similar Mratios in identifying visuo-tactile violation predictions as compared to visuo-temporal violations (but lower than visuospatial). These findings emphasize the importance of tactile information in shaping our experience of acting voluntarily and show how this important component can be experimentally probed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

A compact fingertip-shaped visuo-tactile sensor for manipulator adaptive grasping control

Tactile feedback facilitates monitoring and adjusting the contact state by the manipulator, but operational compliance with the object’s physical properties remains challenging. This paper proposes a fingertip-shaped visuo-tactile sensor (FVTS) compatible with multiple manipulators. The FVTS has micron-level tactile sensitivity and a detection efficiency of 30 fps. On this basis, we propose a two-stage adaptive grasping strategy, leveraging a pre-grasping controller and a stability adjustment controller for micro-contact judgment and grasping stability adjustment. The pre-grasp promotes the manipulator to establish compliance with the object’s physical properties and provides non-invasive grasping protection, then depending on stability adjustment to deepen property cognition. The adaptive grasping tests of fragile, flexible, and heavy objects are performed to evaluate the grasping performance of the manipulator under tactile and non-tactile feedback. The experimental results show that the FVTS has rigid–flexible grasping ability and enhances cognition of physical properties in manipulators, especially providing grasping protection for fragile/flexible objects.

Learning-Based Slip Detection for Dexterous Manipulation Using GelStereo Sensing.

Endowing the robot with tactile perception can effectively improve manipulation dexterity, along with various benefits of human-like touch. Using GelStereo (GS) tactile sensing, which gives high-resolution contact geometry information, including 2-D displacement field, and 3-D point cloud of the contact surface, we present a learning-based slip detection system in this study. The results reveal that the well-trained network achieves 95.79% accuracy on the never-seen testing dataset, which surpasses the current model-based and learning-based methods using visuotactile sensing. We also propose a general framework for slip feedback adaptive control for dexterous robot manipulation tasks. The experimental results show the effectiveness and efficiency of the proposed control framework using GS tactile feedback when deployed on real-world grasping and screwing manipulation tasks on various robot setups.