Data-driven inverse design of flexible pressure sensors.

Artificial skins or flexible pressure sensors that mimic human cutaneous mechanoreceptors transduce tactile stimuli to quantitative electrical signals. Conventional trial-and-error designs for such devices follow a forward structure-to-property routine, which is usually time-consuming and determines one possible solution in one run. Data-driven inverse design can precisely target desired functions while showing far higher productivity, however, it is still absent for flexible pressure sensors because of the difficulties in acquiring a large amount of data. Here, we report a property-to-structure inverse design of flexible pressure sensors, exhibiting a significantly greater efficiency than the conventional routine. We use a reduced-order model that analytically constrains the design scope and an iterative "jumping-selection" method together with a surrogate model that enhances data screening. As an exemplary scenario, hundreds of solutions that overcome the intrinsic signal saturation have been predicted by the inverse method, validating for a variety of material systems. The success in property design on multiple indicators demonstrates that the proposed inverse design is an efficient and powerful tool to target multifarious applications of flexible pressure sensors, which can potentially advance the fields of intelligent robots, advanced healthcare, and human-machine interfaces.

Construction of a Decellularized Multicomponent Extracellular Matrix Interpenetrating Network Scaffold by Gelatin Microporous Hydrogel 3D Cell Culture System.

Interface tissue repair requires the construction of biomaterials with integrated structures of multiple protein types. Hydrogels that modulate internal porous structures provide a 3D microenvironment for encapsulated cells, making them promise for interface tissue repair. Currently, reduction of intrinsic immunogenicity and increase of bioactive extracellular matrix (ECM) secretion are issues to be considered in these materials. In this study, gelatin methacrylate (GelMA) hydrogel is used to encapsulate chondrocytes and construct a phase transition 3D cell culture system (PTCC) by utilizing the thermosensitivity of gelatin microspheres to create micropores within the hydrogel. The types of bioactive extracellular matrix protein formation by chondrocytes encapsulated in hydrogels are investigated in vitro. After 28 days of culture, GelMA PTCC forms an extracellular matrix predominantly composed of collagen type II, collagen type I, and fibronectin. After decellularization, the protein types and mechanical properties are well preserved, fabricating a decellularized tissue-engineered extracellular matrix and GelMA hydrogel interpenetrating network hydrogel (dECM-GelMA IPN) consisting of GelMA hydrogel as the first-level network and the ECM secreted by chondrocytes as the second-level network. This material has the potential to mediate the repair and regeneration of tendon-bone interface tissues with multiple protein types.

Ethylene inhibits ABA-induced stomatal closure via regulating NtMYB184-mediated flavonol biosynthesis in tobacco.

Stomatal movement can be regulated by ABA signaling through synthesis of reactive oxygen species (ROS) in guard cells. By contrast, ethylene triggers the biosynthesis of antioxidant flavonols to suppress ROS accumulation and prevent ABA-induced stomatal closure; however, the underlying mechanism remains largely unknown. In this study, we isolated and characterized the tobacco (Nicotiana tabacum) R2R3-MYB transcription factor NtMYB184, which belongs to the flavonol-specific SG7 subgroup. RNAi suppression and CRISPR/Cas9 mutation (myb184) of NtMYB184 in tobacco caused down-regulation of flavonol biosynthetic genes and decreased the concentration of flavonols in the leaves. Yeast one-hybrid assays, transactivation assays, EMSAs, and ChIP-qPCR demonstrated that NtMYB184 specifically binds to the promoters of flavonol biosynthetic genes via MYBPLANT motifs. NtMYB184 regulated flavonol biosynthesis in guard cells to modulate ROS homeostasis and stomatal aperture. ABA-induced ROS production was accompanied by the suppression of NtMYB184 and flavonol biosynthesis, which may accelerate ABA-induced stomatal closure. Furthermore, ethylene stimulated NtMYB184 expression and flavonol biosynthesis to suppress ROS accumulation and curb ABA-induced stomatal closure. In myb184, however, neither the flavonol and ROS concentrations nor the stomatal aperture varied between the ABA and ABA+ethylene treatments, indicating that NtMYB184 was indispensable for the antagonism between ethylene and ABA via regulating flavonol and ROS concentrations in the guard cells.

Automated quantification of COVID-19 severity and progression using chest CT images.

OBJECTIVE: To develop and test computer software to detect, quantify, and monitor progression of pneumonia associated with COVID-19 using chest CT scans. METHODS: One hundred twenty chest CT scans from subjects with lung infiltrates were used for training deep learning algorithms to segment lung regions and vessels. Seventy-two serial scans from 24 COVID-19 subjects were used to develop and test algorithms to detect and quantify the presence and progression of infiltrates associated with COVID-19. The algorithm included (1) automated lung boundary and vessel segmentation, (2) registration of the lung boundary between serial scans, (3) computerized identification of the pneumonitis regions, and (4) assessment of disease progression. Agreement between radiologist manually delineated regions and computer-detected regions was assessed using the Dice coefficient. Serial scans were registered and used to generate a heatmap visualizing the change between scans. Two radiologists, using a five-point Likert scale, subjectively rated heatmap accuracy in representing progression. RESULTS: There was strong agreement between computer detection and the manual delineation of pneumonic regions with a Dice coefficient of 81% (CI 76-86%). In detecting large pneumonia regions (> 200 mm3), the algorithm had a sensitivity of 95% (CI 94-97%) and specificity of 84% (CI 81-86%). Radiologists rated 95% (CI 72 to 99) of heatmaps at least "acceptable" for representing disease progression. CONCLUSION: The preliminary results suggested the feasibility of using computer software to detect and quantify pneumonic regions associated with COVID-19 and to generate heatmaps that can be used to visualize and assess progression. KEY POINTS: • Both computer vision and deep learning technology were used to develop computer software to quantify the presence and progression of pneumonia associated with COVID-19 depicted on CT images. • The computer software was tested using both quantitative experiments and subjective assessment. • The computer software has the potential to assist in the detection of the pneumonic regions, monitor disease progression, and assess treatment efficacy related to COVID-19.

Any unique image biomarkers associated with COVID-19?

OBJECTIVE: To define the uniqueness of chest CT infiltrative features associated with COVID-19 image characteristics as potential diagnostic biomarkers. METHODS: We retrospectively collected chest CT exams including n = 498 on 151 unique patients RT-PCR positive for COVID-19 and n = 497 unique patients with community-acquired pneumonia (CAP). Both COVID-19 and CAP image sets were partitioned into three groups for training, validation, and testing respectively. In an attempt to discriminate COVID-19 from CAP, we developed several classifiers based on three-dimensional (3D) convolutional neural networks (CNNs). We also asked two experienced radiologists to visually interpret the testing set and discriminate COVID-19 from CAP. The classification performance of the computer algorithms and the radiologists was assessed using the receiver operating characteristic (ROC) analysis, and the nonparametric approaches with multiplicity adjustments when necessary. RESULTS: One of the considered models showed non-trivial, but moderate diagnostic ability overall (AUC of 0.70 with 99% CI 0.56-0.85). This model allowed for the identification of 8-50% of CAP patients with only 2% of COVID-19 patients. CONCLUSIONS: Professional or automated interpretation of CT exams has a moderately low ability to distinguish between COVID-19 and CAP cases. However, the automated image analysis is promising for targeted decision-making due to being able to accurately identify a sizable subsect of non-COVID-19 cases. KEY POINTS: • Both human experts and artificial intelligent models were used to classify the CT scans. • ROC analysis and the nonparametric approaches were used to analyze the performance of the radiologists and computer algorithms. • Unique image features or patterns may not exist for reliably distinguishing all COVID-19 from CAP; however, there may be imaging markers that can identify a sizable subset of non-COVID-19 cases.

Preparation and application of simetryn-imprinted nanoparticles in triazine herbicide residue analysis.

This work provides a simple and rapid method for synthesis uniform simetryn imprinted nanoparticles, which can be used to pretreat the tested samples before detecting. A series of computational approach were employed for design simetryn-imprinted polymer. Based on the conclusion of theoretical calculation, the simetryn imprinted nanoparticles were synthesized using simetryn as template, methacrylic acid as monomer with different solvent volume and synthesis conditions. The obtained nanoparticles have small size, uniform distribution and high imprinted factor. Scatchard analysis and quantum chemical calculations were applied for evaluating the interaction of simetryn with methacrylic acid in the imprinting process. The selectivity and recognition ability of the simetryn imprinted nanoparticles for six triazine herbicides and two other type herbicides were investigated. The results show that the simetryn imprinted nanoparticles had high selectivity and binding capacity and could be used for the separation and enrichment of four triazine pesticide residues from actual samples. A method of molecularly imprinted matrix solid phase extraction ultra-performance liquid chromatography tandem mass spectrometry was established for detecting four kinds of triazine herbicide residues in tobacco. The recovery rate of terbuthylazine, simetryn, atrazine, and prometryn in tobacco was 84.03-119.05%, and the relative standard deviation was 0.35-10.12%.

An efficient TILLING platform for cultivated tobacco.

Targeting-induced local lesions in genomes (TILLING) is a powerful reverse-genetics tool that enables high-throughput screening of genomic variations in plants. Although TILLING has been developed for many diploid plants, the technology has been used in very few polyploid species due to their genomic complexity. Here, we established an efficient capillary electrophoresis-based TILLING platform for allotetraploid cultivated tobacco (Nicotiana tabacum L.) using an ethyl methanesulfonate (EMS)-mutagenized population of 1,536 individuals. We optimized the procedures for endonuclease preparation, leaf tissue sampling, DNA extraction, normalization, pooling, PCR amplification, heteroduplex formation, and capillary electrophoresis. In a test screen using seven target genes with eight PCR fragments, we obtained 118 mutants. The mutation density was estimated to be approximately one mutation per 106 kb on average. Phenotypic analyses showed that mutations in two heavy metal transporter genes, HMA2S and HMA4T, led to reduced accumulation of cadmium and zinc, which was confirmed independently using CRISPR/Cas9 to generate knockout mutants. Our results demonstrate that this powerful TILLING platform (available at http://www.croptilling.org) can be used in tobacco to facilitate functional genomics applications.

Enhanced rutin accumulation in tobacco leaves by overexpressing the NtFLS2 gene.

Rutin, one of the metabolites of the flavonoid pathway, shows great potential in industrial applications as a key component in pharmaceutical medicines and biological pesticides. Although the genetic manipulation of transcription factors (TFs) could increase rutin levels in plants, the accompanying accumulation of structurally similar chemicals complicates industrial rutin extraction. In this study, we demonstrated remarkably elevated rutin content (3.5-4.4-fold relative to controls) in transgenic tobacco plants by overexpressing NtFLS2. The levels of other intermediates in the branch pathway did not change much except for a moderate increase of kaempferol-3-O-rutinoside. Furthermore, the transcript levels of pathway genes in transgenic lines were comparable with controls, indicating genetic engineering did not significantly alter the branch pathway. Additionally, the transgenic tobacco plants appeared normal except for a flower color change from light red to white suggesting that it could be a valuable material for industrial extraction of rutin.

Sorafenib induces autophagic cell death and apoptosis in hepatic stellate cell through the JNK and Akt signaling pathways.

Increasing hepatic stellate cell (HSC) death is an attractive approach for limiting liver fibrosis. We investigated the molecular mechanisms underlying the effects of sorafenib on HSCs. LX2 cells were incubated with sorafenib and a variety of inhibitors of apoptosis, autophagy, and necrosis. Electron microscopy was used to observe autophagosomes. Inhibitors and siRNA were used to examine the role of the Akt/mTOR/p70S6K and JNK pathways. Ultrastructural analysis revealed that rat HSCs treated with 5 µmol/l sorafenib accumulated residual digested material and empty or autophagic vacuoles. Incubating LX2 cells with lysosomal protease inhibitors increased the accumulation of LC3-II, indicating that sorafenib enhances autophagic flux in HSCs. Autophagy may precede apoptosis. Lower concentrations of sorafenib and a shorter treatment time resulted in the dominance of autophagic cell death over apoptosis. Further analysis showed that Beclin 1 is inactivated by the caspases induced by sorafenib during apoptosis. Inhibition of autophagy in LX2 cells using 3-methyladenine treatment or siRNA-mediated knockdown of Atg5 resulted in a marked increase in apoptosis. Finally, sorafenib induced programmed cell death by attenuation and activation of Akt/mTOR/p70S6K and JNK signaling. Sorafenib-induced cell death is mediated by both autophagy and apoptosis. Elucidation of the signaling pathways activated by sorafenib could potentially lead to novel antifibrosis therapies for chronic liver diseases.

A Novel Supra-Brow Combined with Infra-Brow Lift Approach for Asian Women.

BACKGROUND: Direct brow lift surgery remains popular among Asian women despite its disadvantages. The traditional direct brow lift by a supra-brow incision is not suitable for Asian women because of their unique facial features, such as higher eyebrows, wider upper eyelids, and more orbital fat. Therefore, we designed a novel brow lift technique via a supra-brow combined with an infra-brow approach for Asian women. METHODS: An area of skin above and below the eyebrow was measured, demarcated, and surgically removed. The redundant orbicularis oculi muscle (OOM) was excised while keeping the frontalis muscle intact. The OOM in the inferior flap was elevated and sutured to the frontalis muscle. In cases of puffy eyelids, orbital fat was partially removed through an infra-brow incision. Finally, a series of modifications were performed to reduce post-operative scarring. RESULTS: A total of 496 patients underwent this surgery from July 2009 to December 2013 and 432 patients were followed up for at least 6 months after surgery. Post-operative scars, in most patients (428/432), were inconspicuous. There were no facial nerve injuries documented and eight patients reported transient forehead numbness. The height of the palpebral fissure was increased but there was no marked increase observed of the distance between the upper eyelid edge and the eyebrow. In follow-up visits, 409 out of 432 patients (94.7 %) were satisfied with their surgical results. CONCLUSIONS: This new brow lift technique via a supra-brow combined with an infra-brow approach provided a simple and safe surgical repair of lateral brow ptosis, upper eyelids hooding, and crows' feet in Asian women. The surgical outcomes were predictable and the scars were inconspicuous. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Liquid chromatography with mass spectrometry method based two-step precursor ion scanning for the structural elucidation of flavonoids.

Plant flavonoids are very important secondary metabolites for insect and virus control of their host plant and are potent nutrients for humans. To be able to understand the bioavailability and functions of plant flavonoids, it is necessary to reveal their exact chemical structures. Liquid chromatography with tandem mass spectrometry is a powerful approach for structural elucidation of metabolites. In this report, a two-step precursor ion scanning based liquid chromatography with tandem mass spectrometry method was developed for the structural elucidation of plant flavonoids. The established method consists of the two-step precursor ions scanning for possible flavonoids extraction, MS(2) fragment spectra acquisition and comparison with an online database, liquid chromatography retention rules correction, and commercial standards verification. The developed method was used for the structure elucidation of flavonoids in flowers and leaves of tobacco (Nicotiana tabacum), and 17 flavonoids were identified in the tobacco variety Yunyan 97. Nine of the 17 identified flavonoids were considered to be found in tobacco flowers or/and leaves for the first time based on the available references. This method was proved to be very effective and can be used for the identification of flavonoids in other plants.

Dietary flavonoids-microbiota crosstalk in intestinal inflammation and carcinogenesis.

Colorectal cancer (CRC) is currently the third leading cancer and commonly develops from chronic intestinal inflammation. A strong association was found between gut microbiota and intestinal inflammation and carcinogenic risk. Flavonoids, which are abundant in vegetables and fruits, can inhibit inflammation, regulate gut microbiota, protect gut barrier integrity, and modulate immune cell function, thereby attenuating colitis and preventing carcinogenesis. Upon digestion, about 90% of flavonoids are transported to the colon without being absorbed in the small intestine. This phenomenon increases the abundance of beneficial bacteria and enhances the production of short-chain fatty acids. The gut microbe further metabolizes these flavonoids. Interestingly, some metabolites of flavonoids play crucial roles in anti-inflammation and anti-tumor effects. This review summarizes the modulatory effect of flavonoids on gut microbiota and their metabolism by intestinal microbe under disease conditions, including inflammatory bowel disease, colitis-associated cancer (CAC), and CRC. We focus on dietary flavonoids and microbial interactions in intestinal mucosal barriers as well as intestinal immune cells. Results provide novel insights to better understand the crosstalk between dietary flavonoids and gut microbiota and support the standpoint that dietary flavonoids prevent intestinal inflammation and carcinogenesis.

Dual cross-linked COL1/HAp bionic gradient scaffolds containing human amniotic mesenchymal stem cells promote rotator cuff tendon-bone interface healing.

The tendon-bone interface heals through scar tissue, while the lack of a natural interface gradient structure and collagen fibre alignment leads to the occurrence of retearing. Therefore, the promotion of tendon healing has become the focus of regenerative medicine. The purpose of this study was to develop a gradient COL1/ hydroxyapatite (HAp) biomaterial loaded with human amniotic mesenchymal stem cells (hAMSCs). The performance of common cross-linking agents, Genipin, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS), and dual cross-linked materials were compared to select the best cross-linking mechanism to optimize the biological and mechanical properties of the scaffold. The optimal COL1/HAp-loaded with hAMSCs were implanted into the tendon-bone rotator cuff interfaces in rats and the effect on the tendon-bone healing was assessed by micro-CT, histological analysis, and biomechanical properties. The results showed that Genipin and EDC/NHS dual cross-linked COL1/HAp had good biological activity and mechanical properties and promoted the proliferation and differentiation of hAMSCs. Animal experiments showed that the group using a scaffold loaded with hAMSCs had excellent continuity and orientation of collagen fibers, increased fibrocartilage and bone formation, and significantly higher biomechanical functions than the control group at the interface at 12 weeks post operation. This study demonstrated that dual cross-linked gradient COL1/HAp-loaded hAMSCs could promote interface healing, thereby providing a feasible strategy for tendon-bone interface regeneration.

Displacement-pressure biparametrically regulated softness sensory system for intraocular pressure monitoring.

High intraocular pressure (IOP) is one of the high-risk pathogenic factors of glaucoma. Existing methods of IOP measurement are based on the direct interaction with the cornea. Commercial ophthalmic tonometers based on snapshot measurements are expensive, bulky, and their operation requires trained personnel. Theranostic contact lenses are easy to use, but they may block vision and cause infection. Here, we report a sensory system for IOP assessment that uses a soft indentor with two asymmetrically deployed iontronic flexible pressure sensors to interact with the eyelid-eyeball in an eye-closed situation. Inspired by human fingertip assessment of softness, the sensory system extracts displacement-pressure information for soft evaluation, achieving high accuracy IOP monitoring (>96%). We further design and custom-make a portable and wearable ophthalmic tonometer based on the sensory system and demonstrate its high efficacy in IOP screening. This sensory system paves a way towards cost-effective, robust, and reliable IOP monitoring.

Type II collagen scaffolds repair critical-sized osteochondral defects under induced conditions of osteoarthritis in rat knee joints via inhibiting TGF-ß-Smad1/5/8 signaling pathway.

The bidirectional relationship between osteochondral defects (OCD) and osteoarthritis (OA), with each condition exacerbating the other, makes OCD regeneration in the presence of OA challenging. Type II collagen (Col2) is important in OCD regeneration and the management of OA, but its potential applications in cartilage tissue engineering are significantly limited. This study investigated the regeneration capacity of Col2 scaffolds in critical-sized OCDs under surgically induced OA conditions and explored the underlying mechanisms that promoted OCD regeneration. Furthermore, the repair potential of Col2 scaffolds was validated in over critical-sized OCD models. After 90 days or 150 days since scaffold implantation, complete healing was observed histologically in critical-sized OCD, evidenced by the excellent integration with surrounding native tissues. The newly formed tissue biochemically resembled adjacent natural tissue and exhibited comparable biomechanical properties. The regenerated OA tissue demonstrated lower expression of genes associated with cartilage degradation than native OA tissue but comparable expression of genes related to osteochondral anabolism compared with normal tissue. Additionally, transcriptome and proteome analysis revealed the hindrance of TGF-ß-Smad1/5/8 in regenerated OA tissue. In conclusion, the engrafting of Col2 scaffolds led to the successful regeneration of critical-sized OCDs under surgically induced OA conditions by inhibiting the TGF-ß-Smad1/5/8 signaling pathway.

Enhanced hyaline cartilage formation and continuous osteochondral regeneration via 3D-Printed heterogeneous hydrogel with multi-crosslinking inks.

The unique gradient structure and complex composition of osteochondral tissue pose significant challenges in defect regeneration. Restoration of tissue heterogeneity while maintaining hyaline cartilage components has been a difficulty of an osteochondral tissue graft. A novel class of multi-crosslinked polysaccharide-based three-dimensional (3D) printing inks, including decellularized natural cartilage (dNC) and nano-hydroxyapatite, was designed to create a gradient scaffold with a robust interface-binding force. Herein, we report combining a dual-nozzle cross-printing technology and a gradient crosslinking method to create the scaffolds, demonstrating stable mechanical properties and heterogeneous bilayer structures. Biofunctional assessments revealed the remarkable regenerative effects of the scaffold, manifesting three orders of magnitude of mRNA upregulation during chondrogenesis and the formation of pure hyaline cartilage. Transcriptomics of the regeneration site in vivo and scaffold cell interaction tests in vitro showed that printed porous multilayer scaffolds could form the correct tissue structure for cell migration. More importantly, polysaccharides with dNC provided a hydrophilic microenvironment. The microenvironment is crucial in osteochondral regeneration because it could guide the regenerated cartilage to ensure the hyaline phenotype.

Structure Elucidation and Quantitation of 11 N'-n-Acylnornicotines in Cherry-Red Tobacco.

Eleven consecutive N'-n-acylnornicotines from cherry-red tobacco were structurally elucidated and quantitively analyzed using chromatography and mass spectrometry. All of these N'-n-acylnornicotines are first reported in cherry-red tobacco, whereas N'-propionylnornicotine, N'-n-valerylnornicotine, N'-n-nonanoylnornicotine and N'-n-undecanoylnornicotine are first reported in natural products. The concentration distribution of the identified N'-n-acylnornicotines was studied and it was found that N'-n-octanoylnornicotine and N'-n-hexanoylnornicotine showed the highest concentration, accounting for 94% of the detected N'-n-acylnornicotines. The cherry-red color density of the related tobacco leaves was found to be positively correlated with the concentration of the N'-n-acylnornicotines, whereas the ultraviolet-visible spectra of the N'-n-acylnornicotines showed no absorption larger than 300 nm, indicating the discovered compounds are not responsible for the cherry-red color appearance.

Determination of tobacco-specific nitrosamines in tobacco and mainstream cigarette smoke using one-step clean-up coupled with liquid chromatography- tandem mass spectrometry.

A method for determining tobacco-specific nitrosamines (TSNAs) in tobacco and cigarette smoke using liquid chromatography-tandem mass spectrometry was established. The established method amended the deficiencies that exist in current mainstream methods. In this method, TSNAs in tobacco and cigarette smoke were extracted by water. The aqueous extract was then extracted by dichloromethane, and the extract could be analyzed by liquid chromatography-tandem mass spectrometry after a solvent replacement. This method was used to analyze flue-cured tobacco samples, and the response of the target compounds was about 10 times higher than that of the ammonium acetate extraction method. When analyzing cigarette smoke samples, the response strength and chromatographic peak purity of the target compounds were also significantly improved. The proposed method exhibited good linearities for both tobacco and cigarette smoke samples (r2 > 0.99). The limits of detection (LODs) for tobacco and cigarette smoke samples were 0.2-1.0 ng/g and 0.1-0.3 ng/cigarette, respectively. Additionally, this method exhibited desirable accuracy and precision. The TSNAs recovery values from tobacco and cigarette smoke samples ranged from 95.7 % to 107.7 % with inter- and intra-day relative standard deviations (RSDs) of less than 7.4 %. This method is simple, effective, and has wide adaptability. It is a useful upgrade to the existing methods for analyzing TSNAs in tobacco and cigarette smoke.

Embedment of sensing elements for robust, highly sensitive, and cross-talk-free iontronic skins for robotics applications.

Iontronic pressure sensors are promising in robot haptics because they can achieve high sensing performance using nanoscale electric double layers (EDLs) for capacitive signal output. However, it is challenging to achieve both high sensitivity and high mechanical stability in these devices. Iontronic sensors need microstructures that offer subtly changeable EDL interfaces to boost sensitivity, while the microstructured interfaces are mechanically weak. Here, we embed isolated microstructured ionic gel (IMIG) in a hole array (28 × 28) of elastomeric matrix and cross-link the IMIGs laterally to achieve enhanced interfacial robustness without sacrificing sensitivity. The embedded configuration toughens and strengthens the skin by pinning cracks and by the elastic dissipation of the interhole structures. Furthermore, cross-talk between the sensing elements is suppressed by isolating the ionic materials and by designing a circuit with a compensation algorithm. We have demonstrated that the skin is potentially useful for robotic manipulation tasks and object recognition.

A robotic sensory system with high spatiotemporal resolution for texture recognition.

Humans can gently slide a finger on the surface of an object and identify it by capturing both static pressure and high-frequency vibrations. Although modern robots integrated with flexible sensors can precisely detect pressure, shear force, and strain, they still perform insufficiently or require multi-sensors to respond to both static and high-frequency physical stimuli during the interaction. Here, we report a real-time artificial sensory system for high-accuracy texture recognition based on a single iontronic slip-sensor, and propose a criterion-spatiotemporal resolution, to corelate the sensing performance with recognition capability. The sensor can respond to both static and dynamic stimuli (0-400 Hz) with a high spatial resolution of 15 µm in spacing and 6 µm in height, together with a high-frequency resolution of 0.02 Hz at 400 Hz, enabling high-precision discrimination of fine surface features. The sensory system integrated on a prosthetic fingertip can identify 20 different commercial textiles with a 100.0% accuracy at a fixed sliding rate and a 98.9% accuracy at random sliding rates. The sensory system is expected to help achieve subtle tactile sensation for robotics and prosthetics, and further be applied to haptic-based virtual reality and beyond.