Bioinspired Passive Tactile Sensors Enabled by Reversible Polarization of Conjugated Polymers

Tactile perception plays a vital role for the human body and is also highly desired for smart prosthesis and advanced robots.Compared to active sensing devices,passive piezoelectric and triboelectric tactile sensors consume less power,but lack the capability to resolve static stimuli.Here,we address this issue by utilizing the unique polarization chemistry of conjugated polymers for the first time and propose a new type of bioinspired,passive,and bio-friendly tactile sensors for resolving both static and dynamic stimuli.Specifically,to emulate the polarization process of natural sensory cells,conjugated polymers(including poly(3,4-ethylenedioxythiophen e):poly(styrenesulfonate),polyaniline,or polypyrrole)are controllably polarized into two opposite states to create artificial potential differences.The controllable and reversible polarization process of the conjugated polymers is fully in situ characterized.Then,a micro-structured ionic electrolyte is employed to imitate the natural ion channels and to encode external touch stimulations into the variation in potential difference outputs.Compared with the currently existing tactile sensing devices,the developed tactile sensors feature distinct characteristics including fully organic composition,high sensitivity(up to 773 mV N^(−1)),ultralow power consumption(nW),as well as superior bio-friendliness.As demonstrations,both single point tactile perception(surface texture perception and material property perception)and two-dimensional tactile recognitions(shape or profile perception)with high accuracy are successfully realized using self-defined machine learning algorithms.This tactile sensing concept innovation based on the polarization chemistry of conjugated polymers opens up a new path to create robotic tactile sensors and prosthetic electronic skins.

Challenges in the management of visual and tactile hallucinations in elderly people

This letter provides a concise review of the pertinent literature on visual and tactile hallucinations in elderly patients.The discussion addresses differential diagnoses and potential underlying mechanisms,as well as the psychopathology associated with tactile hallucinations,and emphasizes the necessity for invest-igation into the possibility of coexisting delusional infestation(parasitosis).These symptoms frequently manifest in patients with primary psychotic disorders,organic mental disorders,and substance use disorders.The proposed pathophy-siological mechanisms may involve dopaminergic imbalances and dysfunction of the striatal dopamine transporter.

Intelligent Recognition Using Ultralight Multifunctional Nano‑Layered Carbon Aerogel Sensors with Human‑Like Tactile Perception

Humans can perceive our complex world through multi-sensory fusion.Under limited visual conditions,people can sense a variety of tactile signals to identify objects accurately and rapidly.However,replicating this unique capability in robots remains a significant challenge.Here,we present a new form of ultralight multifunctional tactile nano-layered carbon aerogel sensor that provides pressure,temperature,material recognition and 3D location capabilities,which is combined with multimodal supervised learning algorithms for object recognition.The sensor exhibits human-like pressure(0.04–100 kPa)and temperature(21.5–66.2℃)detection,millisecond response times(11 ms),a pressure sensitivity of 92.22 kPa^(−1)and triboelectric durability of over 6000 cycles.The devised algorithm has universality and can accommodate a range of application scenarios.The tactile system can identify common foods in a kitchen scene with 94.63%accuracy and explore the topographic and geomorphic features of a Mars scene with 100%accuracy.This sensing approach empowers robots with versatile tactile perception to advance future society toward heightened sensing,recognition and intelligence.

Intraplantar Injection of Monosodium Iodoacetate Produces Hyperalgesia in Rats and the Mechanism Underlying the Effect

Objective: To observe the effect of intraplantar injection of monosodium iodoacetate (MIA) on pain perception in rats and to investigate the role of transient receptor potential vanilloid type 1 (TRPV1) in the effect. Methods: Adult male Wistar rats were used in the experiment. 1) MIA was injected subcutaneously into the right hindpaw of rats, the low, medium, and high doses of MIA were 0.11, 0.33, and 1 mg, respectively, then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 4 hours after MIA injection were measured. 2) Capsazepine (TRPV1 antagonist, 30 μg) was injected subcutaneously into the right hindpaw of rats at 2 hours after intraplantar injection of MIA (1 mg), then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 1 hour after capsazepine injection were measured. Results: 1) The paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing decreased after intraplantar injection of MIA in rats and the effect lasted for at least 4 hours. 2) The MIA-induced reduction in paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing were significantly alleviated after intraplantar injection of capsazepine in rats. Conclusion: Intraplantar injection of MIA can produce thermal pain, mechanical pain, and spontaneous pain for more than 4 hours, which may be due to the TRPV1 activation caused by MIA.

Influence of Surgical Incision Size and Interleukin 6 in the Occurrence of Postoperative Hyperalgesia in Lubumbashi/DR Congo

Background: It appeared that the conjunction inflammation and nerve damage (caused by surgery) generate the hyperalgesic component. But the probability of predicting hyperalgesia from the size of the surgical incision and/or the resulting inflammatory reaction is not well elucidated. This survey aims to study the influence of the size of the surgical incision and the resulting inflammatory reaction (interleukin 6 levels) in the occurrence of postoperative hyperalgesia in the population of Lubumbashi. Methods: The present study was descriptive cross-sectional. The data collection was prospective over 5 months, from February 1, 2024 to June 30, 2024. This study included any patient over the age of 18 who underwent surgery under general anesthesia. We used indirect signs to define hyperalgesia: higher (ENS > 6) and prolonged pain, postoperative overconsumption of morphine. Results: During our survey, we collected 48 operated patients who had severe postoperative pain, 16 of whom had hyperalgesia, i.e. a prevalence of hyperalgesia of 33.33%. The size of the incision most represented was between ≥20 and i.e. 62.50%. The type of surgery most affected by hyperalgesia was laparotomy. We observed an elevation of IL6 in 87.50% of patients. The largest elevation was 8.91 times the preoperative value and the smallest was 1.04 times. Pre- and postoperative IL6 levels were not associated with hyperalgesia (p = 0.265). Only the size of the surgical incision was associated with hyperalgesia (p = 0.04). Incision size values between [20 - 30] cm were those associated with hyperalgesia (p = 0.027). The model shows that making an incision greater than or equal to 20 cm increases the patient’s risk of developing hyperalgesia by more than 7.222 times and this is statistically significant (p = 0.004). Conclusion: According to this survey, the size of the surgical incision was associated with postoperative hyperalgesia and a size of more than 20 cm increases the patient’s risk of developing hyperalgesia by more than 7.222 times.

Evaluating the Efficacy of Cervical Tactile Ultrasound Technique as a Predictive Tool for Spontaneous Preterm Birth

Background: Premature cervical softening and shortening may be considered an early mechanical failure that predispose to preterm birth. Purpose: This study aims to explore the applicability of an innovative cervical tactile ultrasound approach for predicting spontaneous preterm birth (sPTB). Materials and Methods: Eligible participants were women with low-risk singleton pregnancies in their second trimester, enrolled in this prospective observational study. A Cervix Monitor (CM) device was designed with a vaginal probe comprising four tactile sensors and a single ultrasound transducer operating at 5 MHz. The probe enabled the application of controllable pressure to the external cervical surface, facilitating the acquisition of stress-strain data from both anterior and posterior cervical sectors. Gestational age at delivery was recorded and compared against cervical elasticity. Results: CM examination data were analyzed for 127 women at 240/7 - 286/7 gestational weeks. sPTB was observed in 6.3% of the cases. The preterm group exhibited a lower average cervical stress-to-strain ratio (elasticity) of 0.70 ± 0.26 kPa/mm compared to the term group’s 1.63 ± 0.65 kPa/mm with a p-value of 1.1 × 10−4. Diagnostic accuracy for predicting spontaneous preterm birth based solely on cervical elasticity data was found to be 95.0% (95% CI, 88.5 - 100.0). Conclusion: These findings suggest that measuring cervical elasticity with the designed tactile ultrasound probe has the potential to predict spontaneous preterm birth in a cost-effective manner.

Optical micro/nanofiber enabled tactile sensors and soft actuators:A review

As a combination of fiber optics and nanotechnology,optical micro/nanofiber(MNF)is considered as an important multifunctional building block for fabricating various miniaturized photonic devices.With the rapid progress in flexible optoelectronics,MNF has been emerging as a promising candidate for assembling tactile sensors and soft actuators owing to its unique optical and mechanical properties.This review discusses the advances in MNF enabled tactile sensors and soft actuators,specifically,focusing on the latest research results over the past 5 years and the applications in health monitoring,human-machine interfaces,and robotics.Future prospects and challenges in developing flexible MNF devices are also presented.

Tactile Paving Recognition Method Based on Improved YOLOv7

Tactile paving is a professional road facility to ensure the safe travel of people with visual impairment.However,there are many problems with tactile paving travel in practice.For one,some tactile paving is seriously damaged,and the other is the accumulation of obstacles.How to help visually impaired people recognize and locate obstacles in tactile paving is a problem worth studying.In this paper,image recognition technology is used to recognize the tactile paving pictures with obstacles,and an attention mechanism is used to optimize samples to improve recognition accuracy.

Effects of Neonatal Tactile Stimulation and Maternal Separation on the Anxiety and the Emotional Memory in Adult Female Rats

We investigated the long-lasting effects of early postnatal tactile stimulation （TS） and maternal separation （MS） on the emotional behaviors of adult female rats. A split-litter design was introduced to remove confusing factors such as maternal disturbance. Pups of the non-tactile stimulation （NTS） group did not receive any handling. Pups subjected to the TS treatment were handled and marked for approximately 30 s daily from postnatal days （PND） 2 - 9 or from PND 10 - 17. Pups subjected to the MS treatment were handled and marked in the same way as the TS pups and then individually placed in a cup with familiar nest bedding for 1 h daily. At the age of 3 months, female rats with different neonatal experiences were employed in the light/dark box test and the one-trial passive avoidance response. Both PND 2 - 9 TS and PND 10 - 17 TS groups exhibited more time spent in the illuminated chamber of the light/dark box, and longer step-through latencies in the passive avoidance response when compared to the NTS group, indicating that early life TS treatment reduced novelty-induced anxious emotion and facilitated the retention of emotional memory in adult female rats. No significant effects were found on any behavioral measures between the MS groups and the TS groups, suggesting that neonatal short-time MS treatment was not intensive enough to alter the emotional behaviors, at least in female rats. Infantile age was not an effective factor for these measures. This result supports the hypothesis that neonatal tactile stimulation and maternal separation lead to different effects on the neural development of postnatal pups.

MATERIAL SURFACE THERMAL PROPERTY IDENTIFICATION USING HEAT FLUX TACTILE SENSOR

Eased on the mechanism of temperature tactile sensing of human finger,a heat flux tactile sensor com- posed of a thermostat module and a heat flux sensor is designed to identify material thermal properties. The ther- mostat module maintains the sensor temperature invariable, and the heat flux sensor（Peltier device） detects the heat flux temperature difference between the thermostat module and the object surface. Two different modes of the heat flux tactile sensor are proposed, and they are simulated and experimented for different material objects. The results indicate that the heat flux tactile sensor can effectively identify different thermal properties.

Evaluation of Tactile Comfort of Underwear Fabrics

From the perspective of the tactile comfort of underwear fabrics, 179 kinds of underwear fabrics were selected to test tactile related performance indices using the fabric touch tester(FTT), and the relationship between physical indicators and tactile sensation of different fiber types of underwear fabrics was studied to establish a digital regression model by a stepwise regression method. The experimental results show that fabric fiber composition, compression characteristics, surface friction coefficient, surface roughness amplitude, bending characteristics, and maximum thermal conductivity significantly affect the level of tactile comfort of underwear fabrics, the composition of underwear fabrics has a significant effect on soft touch, and the clustering method and the grading method can effectively rate the level of tactile comfort of underwear fabrics.

TACTILE教学模式在科技英语读写课堂上的应用及有效性研究——一项基于北京邮电大学本科三年级学生的实证研究

世界顶级大学都非常重视思辨能力的培养。而在我国大学英语教学中却普遍存在着“思辨缺席”的问题。本研究以北京邮电大学两个科技英语课堂共121名三年级本科生为被试,尝试将微信平台与TACTILE教学模式整合起来,以对学习者需求分析为基础,为不同学习者定制个性化的学习任务,从而最大限度地提高其学习动机。对学习者的问卷调查和学业测试结果显示这种教学模式得到学生们的认可,对培养学生的思辨能力、语言运用能力以及问题解决能力均取得了良好的效果。

Graphene Nanostructure-Based Tactile Sensors for Electronic Skin Applications

Skin is the largest organ of the human body and can perceive and respond to complex environmental stimulations.Recently,the development of electronic skin(E-skin)for the mimicry of the human sensory system has drawn great attention due to its potential applications in wearable human health monitoring and care systems,advanced robotics,artificial intelligence,and human-machine interfaces.Tactile sense is one of the most important senses of human skin that has attracted special attention.The ability to obtain unique functions using diverse assembly processible methods has rapidly advanced the use of graphene,the most celebrated two-dimensional material,in electronic tactile sensing devices.With a special emphasis on the works achieved since 2016,this review begins with the assembly and modification of graphene materials and then critically and comprehensively summarizes the most advanced material assembly methods,device construction technologies and signal characterization approaches in pressure and strain detection based on graphene and its derivative materials.This review emphasizes on:(1)the underlying working principles of these types of sensors and the unique roles and advantages of graphene materials;(2)state-of-the-art protocols recently developed for high-performance tactile sensing,including representative examples;and(3)perspectives and current challenges for graphene-based tactile sensors in E-skin applications.A summary of these cutting-edge developments intends to provide readers with a deep understanding of the future design of high-quality tactile sensing devices and paves a path for their future commercial applications in the field of E-skin.

Flexible Tactile Electronic Skin Sensor with 3D Force Detection Based on Porous CNTs/PDMS Nanocomposites

Flexible tactile sensors have broad applications in human physiological monitoring,robotic operation and human-machine interaction.However,the research of wearable and flexible tactile sensors with high sensitivity,wide sensing range and ability to detect three-dimensional(3D)force is still very challenging.Herein,a flexible tactile electronic skin sensor based on carbon nanotubes(CNTs)/polydimethylsiloxane(PDMS)nanocomposites is presented for 3D contact force detection.The 3D forces were acquired from combination of four specially designed cells in a sensing element.Contributed from the double-sided rough porous structure and specific surface morphology of nanocomposites,the piezoresistive sensor possesses high sensitivity of 12.1 kPa?1 within the range of 600 Pa and 0.68 kPa?1 in the regime exceeding 1 kPa for normal pressure,as well as 59.9 N?1 in the scope of<0.05 N and>2.3 N?1 in the region of<0.6 N for tangential force with ultra-low response time of 3.1 ms.In addition,multi-functional detection in human body monitoring was employed with single sensing cell and the sensor array was integrated into a robotic arm for objects grasping control,indicating the capacities in intelligent robot applications.

Analgesic action of suspended moxibustion in rats with chronic visceral hyperalgesia correlates with enkephalins in the spinal cord

Rats that modeled chronic visceral hyperalgesia received suspended moxibustion at bilateral Tianshu （ST25） and Shangjuxu （ST37） once daily over a period of 7 days. Results show that suspended moxibustion significantly depressed abdominal withdrawal reflex scores and increased enkephalin concentration in the spinal cord. The experimental findings suggest that spinal enkephalins contributed to the analgesic effect of suspended moxibustion in rats with chronic visceral hyperalgesia.

Mild moxibustion at Tianshu (ST 25) decreases expression of prokineticin-1 and prokineticin receptor-1 in colon tissue of rats with chronic visceral hyperalgesia

Prokineticin-1 and prokineticin receptor-1 play important roles in visceral hypersensitivity and in-flammatory pain. Visceral hypersensitivity is closely associated with irritable bowel syndrome. Mild moxibustion can relieve chronic visceral hyperalgesia in rats with irritable bowel syndrome. We hypothesized that prokineticin-1 and prokineticin receptor-1 is the key target in the mechanism. This study established chronic visceral hyperalgesia rat models by colorectal distention. Protein and mRNA expression of prokineticin-1 and prokineticin receptor-1 were determined by immunohisto-chemical method and fluorescence quantitative-PCR, respectively, and were found to be signifi-cantly increased in visceral hyperalgesic rats. Mild moxibustion at Tianshu （ST 25） decreased prokineticin-1 and prokineticin receptor-1 expression in chronic visceral hyperalgesia rats and lessen the chronic visceral hyperalgesia in rats with irritable bowel syndrome at different levels of colorectal distention pressure.

Shugan-decoction relieves visceral hyperalgesia and reduces TRPV1 and SP colon expression

AIM:To evaluate the therapeutic effect of Shugan-decoction(SGD)on visceral hyperalgesia and colon gene expressions using a rat model.METHODS:Ninety-six adult male Wistar rats were randomized into six equal groups for assessment of SGD effects on psychological stress-induced changes using the classic water avoidance stress(WAS)test.Untreated model rats were exposed to chronic(1 h/d for 10 d consecutive)WAS conditions;experimental treatment model rats were administered with intragastric SGD at1 h before WAS on consecutive days 4-10(low-dose:0.1g/mL;mid-dose:0.2 g/mL;high-dose:0.4 g/mL);control treatment model rats were similarly administered with the irritable bowel syndrome drug,dicetel(0.0042g/mL);untreated normal control rats received no drug and were not subjected to the WAS test.At the end of the 10-d WAS testing period,a semi-quantitative measurement of visceral sensitivity was made by assessing the abdominal withdrawal reflex(AWR)to colorectal balloon-induced distension(at 5 mmHg increments)to determine the pain pressure threshold(PPT,evidenced by pain behavior).Subsequently,the animals were sacrificed and colonic tissues collected for assessment of changes in expressions of proteins related to visceral hypersensitivity(transient receptor potential vanilloid 1,TRPV1)and sustained visceral hyperalgesia(substance P,SP)by immunohistochemistry and real-time polymerase chain reaction.Inter-group differences were assessed by paired t test or repeated measures analysis of variance.RESULTS:The WAS test successfully induced visceral hypersensitivity,as evidenced by a significantly reduced AWR pressure in the untreated model group as compared to the untreated normal control group(190.4±3.48 mmHg vs 224.0±4.99 mmHg,P<0.001).SGD treatments at mid-dose and high-dose and the dicetel treatment significantly increased the WAS-reduced PPT(212.5±2.54,216.5±3.50 and 217.7±2.83 mmHg respectively,all P<0.001);however,the low-dose SGD treatment produced no significant effect on the WAS-reduced PPT(198.3±1.78 mmHg,P>0.05).These trends corresponded to the differential expressions observed for both TRPV1 protein(mid-dose:1.64±0.08 and high-dose:1.69±0.12 vs untreated model:3.65±0.32,P<0.001)and mRNA(0.44±0.16 and0.15±0.03 vs 1.39±0.15,P<0.001)and SP protein(0.99±0.20 and 1.03±0.23 vs 2.03±0.12,P<0.01)and mRNA(1.64±0.19 and 1.32±0.14 vs 2.60±0.33,P<0.05).These differential expressions of TRPV1 and SP related to mid-and high-dose SGD treatments were statistically similar to the changes induced by dicetel treatment.No signs of overt damage to the rat system were observed for any of the SGD dosages.CONCLUSION:Shugan-decoction can reduce chronic stress-induced visceral hypersensitivity in rats,and the regulatory mechanism may involve mediating the expressions of TRPV1 and SP in colon tissues.

Properties of tactile responses of neurons in rat thalamic ventroposterolateral nucleus

Objective To determine whether the convergences of tactile information also occur at thalamic ventroposterolateral nucleus in rats, we investigated the properties of tactile responses of the thalamic ventroposterolateral nucleus in rats. Methods Unit responses were recorded extracellularly from thalamic ventroposterolateral nucleus in anesthetized rats. Results Among 156 neurons examined, 140 neurons （89.7%） had the single, continual and small receptive fields, and 16 neurons （10.3%） had two discrete receptive fields. Some neurons exhibited different responses to the same intensity stimulation which delivered to different points in their receptive fields. In addition, 4.5% neurons （n -- 7） responded only to locomotive stimulation but not to a punctiform tactile stimulation. Conclusion The majority of neurons in ventroposterolateral nucleus of rats have the spatial, temporal and submodal characteristics of cutaneous receptors, while the minority of neurons exhibit the responses of interaction of different peripheral receptors. Therefore, it is con- cluded that there are convergences of tactile information at the ventroposterolateral nucleus of rats.

Bilateral mechanical and thermal hyperalgesia and tactile allodynia after chronic compression of dorsal root ganglion in mice

Objective Low back pain is one of the most inextricable problems encountered in clinics. Animal models that imitate symptoms in humans are valuable tools for investigating low back pain mechanisms and the possible therapeutic applications. With the development of genetic technology in pain field, the possibility of mutating specific genes in mice has provided a potent tool for investigating the specific mechanisms of pain. The aim of the present study was to develop a mouse model of chronic compression of dorsal root ganglion （CCD）, in which gene mutation can be applied to facilitate the studies of chronic pain. Methods Chronic compression of L4 and L5 dorsal root ganglia was conducted in mice by inserting fine stainless steel rods into the intervertebral foramina, one at L4 and the other at L5. Mechanical allodynia and thermal hyperalgesia were examined with von Frey filaments and radiating heat stimulator, respectively. Results The CCD mice displayed dramatic mechanical and thermal hyperalgesia as well as tactile allodynia in the hindpaw ipsilateral to CCD. In addition, this mechanical and thermal hyperalgesia as well as tactile allodynia was also found to spread to the contralateral hindpaw. Conclusion This model, combined with the possible genetic modification, will strengthen our knowledge of the underlying mechanisms of low back pain. It also favors the development of new treatment strategies for pain and hyperalgesia after spinal injury and other disorders which affect the dorsal root ganglion in humans.

Puerarin ameliorates allodynia and hyperalgesia in rats with peripheral nerve injury

Puerarin is a major active ingredient of the traditional Chinese plant medicine,Radix Puerariae,and commonly used in the treatment of myocardial and cerebral ischemia.However,the effects of puerarin on neuropathic pain are still unclear.In this study,a neuropathic pain animal model was created by partial sciatic nerve ligation.Puerarin（30 or 60 mg/kg） was intraperitoneally injected once a day for 7 days.Mechanical allodynia and thermal hyperalgesia were examined at 1 day after model establishment.Mechanical threshold and paw withdrawal latency markedly increased in a dose-dependent manner in puerarin-treated rats,especially at 7 days after model establishment.At 7 days after model establishment,quantitative real-time reverse transcriptase-polymerase chain reaction results showed that puerarin administration reversed m RNA expression of transient receptor potential vanilloid 1（Trpv1） and transient receptor potential ankyrin 1（Trpa1） in a dose-dependent manner in dorsal root ganglion neurons after peripheral nerve injury.These results suggest that puerarin dose-dependently ameliorates neuropathic pain by suppressing Trpv1 and Trpa1 up-regulation in dorsal root ganglion of neuropathic pain rats.