Smart Patch Research Articles

(Digital Presentation) Electrocatalytic Cortisol Tracing Smart Patch

Rapid and continuous tracking of the stress hormone cortisol's circadian rhythm is vital for diagnosing diseases related to chronic stress and adrenal gland disorders [1]. Commercial cortisol sensors relying on labeled enzyme and antibodies suffer from limited stability, lengthy reaction time, and cross-reactivity with analogous molecules [2]. To address these issues, we developed an electrocatalytic sensor using phthalocyanine (Pc) doped molecularly imprinted polymer (MIP) modified screen-printed electrodes for label-free, reagentless, sensitive, and selective electrochemical detection of cortisol. The sensor was constructed via one-step electropolymerization of conductive prepolymer in the presence of Pc and template cortisol. The controlled release of cortisol templates resulted in an MIP network embedded with Pc catalysts in the vicinity of the cortisol-specific binding cavities. The sensor directly measures the cortisol level by catalysing the reduction reaction of the cortisol captured by the cavities of the MIP. Proof of studies was performed to detect cortisol over a wide concentration range varying from 500 pM to 10 µM with high selectivity against structurally similar hormones. The facile label-free and antibody-free cortisol sensor on a wearable smart patch offers an appealing approach for selective steroid hormone detection at point-of-care testing.

Conductive Microneedle Patch with Electricity-Triggered Drug Release Performance for Atopic Dermatitis Treatment.

Atopic dermatitis (AD) is a chronic inflammatory skin disease that seriously affects the life quality of patients. Topical administration of glucocorticoids is considered to be the most effective anti-inflammatory treatment. However, due to the barrier function of skin, only less than 20% of topical drug molecules could diffuse into the skin. Therefore, it is of great importance to develop an effective strategy to improve AD therapy. In this study, we reported a two-electrode microneedle patch (t-EMNP) composed of a polylactic acid-platinum (PLA-Pt) MN array and polylactic acid-platinum-polypyrrole (PLA-Pt-PPy) MN array for improving the transdermal drug delivery efficacy. The drug loading capability of MNs could be altered by employing different polymerization times and drug concentrations. The drug release rate of MNs could be changed by applying different voltages. We further developed a controlled transdermal drug delivery system (c-TDDS) based on this two-electrode microneedle patch (t-EMNP), exhibiting the remarkable performance of the electricity-triggered drug release profile. The drugs could be released with electrical stimulation, while there was almost no drug release without electrical stimulation. For AD treatment in vivo, this MN patch with electricity-triggered drug release performance could effectively deliver more drugs into the skin compared with other controls such as dexamethasone cream, which efficiently alleviate AD. In sum, this work not only developed a smart patch for improving AD treatment but also provided a promising approach of transdermal drug delivery on demand.

A Comparison of a Novel Stretchable Smart Patch for Measuring Runner's Step Rates with Existing Measuring Technologies.

A novel wearable smart patch can monitor various aspects of physical activity, including the dynamics of running, but like any new device developed for such applications, it must first be tested for validity. Here, we compare the step rate while running in place as measured by this smart patch to the corresponding values obtained utilizing ‘‘gold standard’’ MEMS accelerometers in combination with bilateral force plates equipped with HBM load cells, as well as the values provided by a three-dimensional motion capture system and the Garmin Dynamics Running Pod. The 15 healthy, physically active volunteers (age = 23 ± 3 years; body mass = 74 ± 17 kg, height = 176 ± 10 cm) completed three consecutive 20-s bouts of running in place, starting at low, followed by medium, and finally at high intensity, all self-chosen. Our major findings are that the rates of running in place provided by all four systems were valid, with the notable exception of the fast step rate as measured by the Garmin Running Pod. The lowest mean bias and LoA for these measurements at all rates were associated consistently with the smart patch.

A Soft and Skin-Interfaced Smart Patch Based on Fiber Optics for Cardiorespiratory Monitoring.

Wearables are valuable solutions for monitoring a variety of physiological parameters. Their application in cardiorespiratory monitoring may significantly impact global health problems and the economic burden related to cardiovascular and respiratory diseases. Here, we describe a soft biosensor capable of monitoring heart (HR) and respiratory (RR) rates simultaneously. We show that a skin-interfaced biosensor based on fiber optics (i.e., the smart patch) is capable of estimating HR and RR by detecting local ribcage strain caused by breathing and heart beating. The system addresses some of the main technical challenges that limit the wide-scale use of wearables, such as the simultaneous monitoring of HR and RR via single sensing modalities, their limited skin compliance, and low sensitivity. We demonstrate that the smart patch estimates HR and RR with high fidelity under different respiratory conditions and common daily body positions. We highlight the system potentiality of real-time cardiorespiratory monitoring in a broad range of home settings.

A hybrid sensor for motor tics recognition based on piezoelectric and triboelectric design and fabrication

With the gradual development of various artificial electronic skins and smart patches and other wearable electronic products, the collection of biomechanical energy to achieve self-powered sensing is critical to achieving the efficient function and sustainability of the system. In this work, a study of a novel hybrid sensor fabricated based on the piezoelectric and triboelectric design for motor tics recognition will be presented. A plant bionic and flexible hybrid self-powered sensor (PBHS) for motor tics recognition is reported. By combining bionic polydimethylsiloxane (PDMS) triboelectric nanogenerator and a layered stacked porous polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) nanofiber piezoelectric nanogenerator in mixing through near-field electrospinning (NFES) process on the flexible printed circuit board (FPCB) substrate, this enables the sensor which is a layer-by-layer stacked porous PVDF-TrFE nanofiber (LPPN) mainly composed of about 2500 piezoelectric polymers as a height of 2.2 mm thin wall to enhance energy harvesting characteristics. Compared with the original PVDF-TrFE nanogenerator, the voltage output performance is nearly reached to 5 V as a ~200% improvement. Furthermore, a self-powered tics recognition system has been developed through deep learning to provide doctors to observe the status of patients with motor tics of Tourette syndrome. By using the deep learning model of long short-term memory (LSTM) of a type of recurrent neural network (RNN), the overall sequences hybrid signal recognition rate for tic recognition has been achieved to 88.1%.

Smart Patch for Structural Health Monitoring of Composite Repair

The bondline integrity of a repair patch to the parent composite laminate is considered the most important factor in the repair design. A smart repair patch is proposed here to allow for real-time ultrasonic guided wave monitoring of repaired composites. A diagnostic film with lead zirconate titanate (PZT) transducers and inkjet-printed wires is embedded into the repair patch using a cut-out method. The electro-mechanical impedance (EMI) method is used to verify the integrity of the embedded PZT transducers. The performance of the smart repair patch is assessed on the external panel with artificial bondline delamination and surface-mounted artificial damage. The damage index correlation coefficient and delay-and-sum (DAS) algorithm are used for damage detection and localization. The results show that the developed repair patch can successfully detect and locate damages.

Coordination polymer nanozymes-integrated colorimetric microneedle patches for intelligent wound infection management

Biomedical patches are playing an indispensable role in wound infection management. Current efforts have focused on designing smart patches with both treating and sensing abilities to recognize wound infections and kill bacteria efficiently. Here, we present intelligent colorimetric microneedle patches (MNs) integrated with Fe ion-gallic acid coordination polymer nanodots (FNDs) for on-demand treatment and real-time report of infected wounds. Such FNDs are fabricated by coordination reactions among polyvinylpyrrolidone (PVP), gallic acid, and Fe ion, and are loaded inside the MNs using a template replication method (FNDs-MNs). Benefitting from the pH-dependent peroxidase mimic activity of the FNDs, the integrated MNs can catalyze H2O2 to generate much more OH at the acidic condition for bacteria killing. Besides, these FNDs-MNs also possess pH and H2O2 dependent color changes, and thus can timely reflect the wound repair and infection states. During the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infected wounds in mice, the FNDs-MNs exhibit obvious color changes at infected stages and achieve on-demand therapeutic effects. Thus, it is believed that such FNDs-MNs have great potentials for efficient wound infection management and will find wide applications in wound care.

Self-powered smart patch promotes skin nerve regeneration and sensation restoration by delivering biological-electrical signals in program

Skin wound is always accompanied with nerve destruction. Due to the limited clinical treatment option, loss of skin sensation with unsatisfactory nerve regeneration is remained to be a challenge for wound therapy. Endogenous mesenchymal stem cells (MSCs) based in situ regeneration, of which, MSCs recruited by chemokines and directed for neuronal differentiation by biological and electrical signals have been thought a novel strategy with potential to accelerate the nerve regeneration and sensory functions recovery. However, most current therapeutic systems usually deliver the chemokines, biological and electrical signals separately and statically, resulting in limited nerve regeneration and sensory functions recovery. Moreover, most of the devices for providing electrical signals need external energy input and complicated practice, leading to poor compliance in patients. To address these issues, we propose a self-powered smart patch (PRG-G-C) to provide chemokine and biological-electrical cues in program. PRG-G-C was composed of a flexible piezoelectric generator to supply electrical stimulation and a conductive gel, which served as the reservoir of chemokine and neural directing exosomes as well as the electrode to transfer electric cue. PRG-G-C was shown to efficiently accelerate rapid nerve regeneration and sensation restoration at the wound site within 23 days. This study demonstrates a proof-to-concept in organizing chemokine, neural directing biological-electrical heterogeneous cues within a self-powered smart patch for accelarating nerve regeneration and sensation restoration, possessing great potential in neural repair applications.

Flexible, Wearable and Fully-printed Smart Patch for pH and Hydration Sensing in Wounds.

Wound healing is a complex and dynamic regeneration process, wherein the physical and chemical parameters are continuously changing. Its management and monitoring can provide immense benefits, especially for bed-ridden patients. This work reports a low-cost, flexible, and fully printed on-skin patch sensor to measure the change in pH and fluid content in a wound. Such a bendable sensor can also be easily incorporated in a wound dressing. The sensor consists of different electrodes printed on polydimethylsiloxane (PDMS) substrate for pH and moisture sensing. The fabricated sensor patch has a sensitivity of 7.1 ohm/pH for wound pH levels. The hydration sensor results showed that moisture levels on a semi-porous surface can be quantified through resistance change.

Improving Dyspnoea Symptom Control of Patients in Palliative Care Using a Smart Patch-A Proof of Concept Study.

The world of healthcare constantly aims to improve the lives of people while nurturing their health and comfort. Digital health and wearable technologies are aimed at making this possible. However, there are numerous factors that need to be addressed such as aging, disabilities, and health hazards. These factors are intensified in palliative care (PC) patients and limited hospital capacities make it challenging for health care providers (HCP) to handle the crisis. One of the most common symptoms reported by PC patients with severe conditions is dyspnoea. Monitoring devices with sufficient comfort could improve symptom control of patients with dyspnoea in PC. In this article, we discuss the proof-of-concept study to investigate a smart patch (SP), which monitors the pulmonary parameters: (a) breathing rate (BR) and inspiration to expiration ratio (I:E); markers for distress: (b) heart rate (HR) and heart rate variability (HRV), and (c) transmits real-time data securely to an adaptable user interface, primarily geared for palliative HCP but scalable to specific needs. The concept is verified by measuring and analyzing physiological signals from different electrode positions on the chest and comparing the results achieved with the gold standard Task Force Monitor (TFM).

Photovoltaic and triboelectrification empowered light-weight flexible self-charging asymmetric supercapacitor cell for self-powered multifunctional electronics

Herein, we highlight the simplistic fabrication of a light-weight, flexible self-charging power pack by the prudent integration of two paper-based high-performance triboelectric nanogenerators (HPTENGs), one commercial semi-flexible photovoltaic/solar cell and a paper-based all-solid-state asymmetric-type supercapacitor (ASSASC) with optimized performance. Each HPTENG unit comprises of a ~20 wt% barium titanate nanoparticles loaded surface micropatterned post-polled PDMS composite (PDMS–20BTO) film-strip impregnated with graphite coated Whatman® 41 filter paper (GFP) as negative and a polypyrrole electrodeposited GFP as positive triboelectric friction layers, respectively. Contrariwise, the ASSASC consists of a nickel-cobalt-molybdenum oxide–graphitic C3N4 hybrid composite coated GFP (NCMO–gCN2/GFP) as positive and a graphitic C3N4 modified reduced graphene oxide coated GFP (gCN–m–RGO/GFP) as negative electrodes, separated by a thin PVA–KOH gel-type electrolyte membrane. Finally, under deformations/stress and illumination of solar light individually on top of our photovoltaic and HPTENGs driven self-charging ASSASC (PTSCASC) power pack, it efficaciously generates electrical energy and consequently stores this generated energy as electrochemical energy for sustainable power supply. Our self-powered PTSCASC# power pack prototype (with two ASSASCs) has been effectually integrated with a medical smart patch for electric pulsatile mediated controlled drug release. Hence, our as-designed self-charging power pack possesses immense potentials for self-powered multifunctional electronics and smart e-healthcare monitoring systems.

Piezoelectric Smart Patch Operated with Machine-Learning Algorithms for Effective Detection and Elimination of Condensation.

Timely detection and elimination of surface condensation is crucial for diverse applications in agriculture, automotive, oil and gas industries, and respiratory monitoring. In this paper, a smart patch based on a ZnO/aluminum (∼5 μm/50 μm thick) flexible Lamb wave device has been proposed to detect, prevent, and eliminate condensation, which can be realized using both of its surfaces. The patch is operated using a machine-learning algorithm which consists of data preprocessing (feature selection and optimization) and model training by a random forest algorithm. It has been tested in six cases, and the results show good detection performance with average precision = 94.40% and average F1 score = 93.23%. The principle of accelerating evaporation is investigated to understand the elimination and prevention functions for surface condensation. Results show that both dielectric heating and acoustothermal effect have their contributions, whereas the former is found more dominant. Furthermore, the functional relationship between the evaporation rate and the input power is calibrated, showing a high linearity (R2 = 97.64%) with a slope of ∼3.6 × 10-5 1/(s·mW). With an input power of ∼0.6 W, the flexible device has been proven effective in the prevention of condensation.

Pilot Study on Reducing Symptoms of Anxiety with a Heart Rate Variability Biofeedback Wearable and Remote Stress Management Coach.

We assessed the feasibility of using a consumer friendly, heart rate variability biofeedback (HRVB) wearable device in conjunction with a remote stress management coach to reduce symptoms of anxiety. We utilized a discreet, continuously wearable electrocardiogram device, the Lief Smart Patch, which measures and records heart rate and HRV in real time, and guides HRVB exercises using vibrations and visual cues. During the 8-week study, participants (N = 14) wore the Lief Smart Patch, participated in HRVB with the device, utilized the mobile app, and communicated with a remote stress management coach. We collected self-report survey responses to measure symptoms of anxiety (GAD-2) and depression (PHQ-2) every 2 weeks, as well as HRV data throughout the study. Participants’ mean GAD-2 score began at 4.6 out of 6. By the trial’s completion, the group’s mean GAD-2 score dropped to 1.7 (t(13) = 11.0, p < .001) with only 2 of the 14 subjects remaining over the clinical threshold of high anxiety. Similarly, the group’s mean PHQ-2 score dropped from 2.93 to 1.29 (t(13) = 3.54, p < .01). In addition, participants increased their HRV (RMSSD) by an average of + 11.4 ms after participating in a low dose biofeedback exercise. These findings suggest that engaging in HRVB through a discreet wearable device in conjunction with a remote stress management program may be effective for reducing symptoms of anxiety and depression.

On-Site Longitudinal Monitoring of Crop Health Using Vapor-Printed Polymer Tattoos

Emergent wearable health-monitoring devices use a tissue-adhered electrode as their sensing element, which is typically created by applying a preformed polymer, nanoparticle/nanowire or carbon material film onto the outer surface of an organism. However, the surfaces of organisms display staggeringly diverse microscale features, and the complex biochemical, mechanical and transport phenomena that operate at the interface between such microstructured living tissue and a man-made device ultimately control the performance and longevity of tissue-adhered electrodes. Contemporary stick-and-play devices, such as smart patches and press-on buttons, are often susceptible to device delamination from the surface of living organisms and, often, perturb air/water/nutrient transport at the biointerface, reducing long-term viability. We demonstrate a new paradigm for vapor printing biocompatible polymer films directly onto a living organism, creating conformal and long-lasting electrodes that allow for long-term health monitoring using bioimpedance measurements. This approach enables on-site and longitudinal monitoring of otherwise hard to track abiotic stressors, such as ozone damage, even at low exposure levels. Oxidative damage produces a unique change in the high-frequency (>104 Hz) impedance and phase signals of leaves, which is not replicated by other abiotic stressors, such as drought. The polymer tattoos are resilient against ozone-induced chemical degradation and persist on the leaves of fruiting plants, thus allowing for frequent and long-term monitoring of cellular ozone damage in economically important crops, such as grapes and apples.

Smart Patch for Skin Temperature: Preliminary Study to Evaluate Psychometrics and Feasibility.

There is a need for continuous, non-invasive monitoring of biological data to assess health and wellbeing. Currently, many types of smart patches have been developed to continuously monitor body temperature, but few trials have been completed to evaluate psychometrics and feasibility for human subjects in real-life scenarios. The aim of this feasibility study was to evaluate the reliability, validity and usability of a smart patch measuring body temperature in healthy adults. The smart patch consisted of a fully integrated wearable wireless sensor with a multichannel temperature sensor, signal processing integrated circuit, wireless communication feature and a flexible battery. Thirty-five healthy adults were recruited for this test, carried out by wearing the patches on their upper chests for 24 h and checking their body temperature six times a day using infrared forehead thermometers as a gold standard for testing validity. Descriptive statistics, one-sampled and independent t-tests, Pearson’s correlation coefficients and Bland-Altman plot were examined for body temperatures between two measures. In addition, multiple linear regression, receiver operating characteristic (ROC) and qualitative content analysis were conducted. Among the 35 participants, 29 of them wore the patch for over 19 h (dropout rate: 17.14%). Mean body temperature measured by infrared forehead thermometers and smart patch ranged between 32.53 and 38.2 °C per person and were moderately correlated (r = 0.23–0.43) overall. Based on a Bland-Altman plot, approximately 94% of the measurements were located within one standard deviation (upper limit = 4.52, lower limit = −5.82). Most outliers were identified on the first measurement and were located below the lower limit. It is appropriate to use 37.5 °C in infrared forehead temperature as a cutoff to define febrile conditions. Users’ position while checking and ambient temperature and humidity are not affected to the smart patch body temperature. Overall, the participants showed high usability and satisfaction on the survey. Few participants reported discomfort due to limited daily activity, itchy skin or detaching concerns. In conclusion, epidermal electronic sensor technologies provide a promising method for continuously monitoring individuals’ body temperatures, even in real-life situations. Our study findings show the potential for smart patches to monitoring non-febrile condition in the community.

A Combination of Coconut Fiber Suture and Tamarind Seed Gel with Dehydrated Human Amnion Membrane for Wound Surgery in Rats

Today, there are over 2,000 different biomaterials used for various medical applications, but none of these biomaterials are 100% compatible with all human beings. Coconut fiber is widely available but has not been tested as a safe natural alternative for sutures. Immature coconut fiber is nonabsorbable and is effective for cuts and open wounds when used in combination with dehydrated human amnion membrane (dHAM). Immature coconut fiber, tamarind seed polysaccharide (TSP), and dHAM were prepared to test their combinational effect on wound healing in rats. TSP enhanced cell viability, proliferation, and migration in human skin cells and cured wounds both individually and in combination with dHAM. An antibiotic‐free combination of the human amniotic membrane with intact epithelium, tamarind seed polysaccharide, and immature coconut fiber provided faster wound healing. Significantly higher wound healing was seen on the 11th day based on an initial 10 mm biopsy punch surgery in Wistar rats compared to control groups. Histological studies revealed thickened dermis edges with more neutrophil infiltration. Collagen deposition in the dermis was homogeneous across the excised skin tissue in the test group, again attesting to the utility of this procedure. This research signifies the use of TSP gel together with the amnion membrane representing a “smart patch” with wound healing potential, which would encourage further research on the smart patch made using a combination of plant and animal biological materials.

Impact of stain normalization and patch selection on the performance of convolutional neural networks in histological breast and prostate cancer classification

BackgroundRecently, deep learning has rapidly become the methodology of choice in digital pathology image analysis. However, due to the current challenges of digital pathology (color stain variability, large images, etc.), specific pre-processing steps are required to train a reliable deep learning model. MethodIn this work, there are two main goals: i) present a fully automated pre-processing algorithm for a smart patch selection within histopathological images, and ii) evaluate the impact of the proposed strategy within a deep learning framework for the detection of prostate and breast cancer. The proposed algorithm is specifically designed to extract patches only on informative regions (i.e., high density of nuclei), most likely representative of where cancer can be detected. ResultsOur strategy was developed and tested on 1000 hematoxylin and eosin (H&E) stained images of prostate and breast tissue. By combining a stain normalization step and a segmentation-driven patch extraction, the proposed approach is capable of increasing the performance of a computer-aided diagnosis (CAD) system for the detection of prostate cancer (18.61% accuracy improvement) and breast cancer (17.72% accuracy improvement). ConclusionWe strongly believe that the integration of the proposed pre-processing steps within deep learning frameworks will allow the achievement of robust and reliable CAD systems. Being based on nuclei detection, this strategy can be easily extended to other glandular tissues (e.g., colon, thyroid, pancreas, etc.) or staining methods (e.g., PAS).

Minimally Invasive Electrochemical Patch-Based Sensor System for Monitoring Glucose and Lactate in the Human Body-A Survey-Based Analysis of the End-User's Perspective.

Background: Wearable electrochemical sensors that detect human biomarkers allow a comprehensive analysis of a person’s health condition. The “electronic smart patch system for wireless monitoring of molecular biomarkers for health care and well-being” (ELSAH) project aims to develop a minimally invasive sensor system that is capable of continuously monitoring glucose and lactate in the dermal interstitial fluid in real time. It is the objective of the present study to compare the intended ELSAH-patch specifications with the expectations and requirements of potential end-users at an early stage during the development phase. Methods: A questionnaire addressing different aspects of the ELSAH-patch was filled out by 383 respondents. Results: The participants stated a high general demand for such a system, and they would use the ELSAH-patch in different health care and physical fitness applications. The preferred terminal device for communication with the sensor would be the smartphone. An operating time of 24 hours would be sufficient for 55.8% of the users (95%-CI: 50.3–61.3%), while 43.5% of them (95%-CI: 38.0–48.9%) would prefer a lifetime of several days or more. The software should have a warning function, especially for critical health conditions. Since the measured personal data would be highly sensitive, the participants called for high standards for data security and privacy. Conclusion: In general, the participants’ responses on their expectations and requirements were well in line with the intended specifications of the ELSAH-patch system. However, certain technical aspects such as the lifetime, data security and accuracy require special attention during its development.

Ultrasound-induced deformation of PLGA-microPlates for on-command drug release

Transdermal drug delivery offers several advantages over other conventional modalities for drug administration, such as injections and oral administrations. It can be activated by exogenous energy sources, including electric and magnetic fields, or by light and ultrasound (US). Ultrasound can induce the degradation and deformation of a polymeric matrix, thus promoting the release of entrapped drugs and the topical administration through the skin. Our aim is to create a wearable patch composed of an ultrasound-responsive polymeric system encapsulating specific drugs, which are released on demand by the application of ultrasound. In this work, we investigate the effect of ultrasound on square poly(lactic-co-glycolic acid) (PLGA) microparticles loaded with curcumin (CURC), called curcumin-microplates (CURC-μPLs), realized using a top-down fabrication process. Using Finite Element Method (FEM) simulations, we identified the resonant frequencies and the mode shape of the μPLs. Guided by this simulation, we applied ultrasound stimulus at frequency of 1 MHz, close to the first mechanical resonance frequency of the microplates, leading to a 200% increase in CURC release rate after 30 min of ultrasonic treatment. This approach can be generalized to any ultrasound-sensitive matrix filled with specific drugs and with piezoelectric compliant transducers embedded in the smart patch for generating ultrasonic waves.

Self-powered flexible and transparent smart patch for temperature sensing

Wearable electronics that can deform with human skin and monitor physical information are promising next-generation electronics. Here, we demonstrate a self-powered smart patch for temperature sensing by integrating a triboelectric nanogenerator, power management circuit and temperature sensor together. Benefitting from the functional nanomaterial and fabrication process of spray coating, the main part of the device shows extraordinary mechanical flexibility and visible transparency. The temperature sensor presents a high sensitivity of 0.54% per Kelvin scaled by relative resistance change. Owing to the high efficiency of the implemented power management circuit, a capacitor of 100 μF can be easily charged to 1 V within 105 s through the triboelectric nanogenerator contacting with cotton, which can drive the sensor continuously to work for more than 100 s. The large-scalable fabrication process and integration design give this smart patch potential applications in human-machine interfaces and soft electronic skins.