Search Results (5)

Conductive silicone interfaces are promising polymeric materials for wearable bioelectronic systems because they combine electrical continuity with elastomeric compliance, environmental durability, and moldability. In low-voltage wearable microcurrent interfaces, however, functional performance is governed not only by intrinsic material conductivity, but also by conductive network continuity, molded geometry, interfacial contact, and transient electrical response. In this study, we developed a spike-structured conductive silicone interface using a commercially available electrically conductive two-component silicone rubber and investigated its structure–electrical property relationships as a volume-resistive polymer interface. The interface consisted of a conductive silicone body with protrusions 7 mm in height and 3.6 mm in diameter, supported by a 1 mm base layer and electrically integrated through an Ag-paste-connected upper conduction region. Using a representative electrode-level resistance of 47.08 Ω, the geometry-derived apparent interfacial resistive response was estimated as 18.0 Ω·cm for the three-spike configuration and 24.0 Ω·cm for the four-spike configuration. The corresponding effective conductive areas were 0.305 cm² and 0.407 cm², respectively, giving analytical current-density amplification factors of 9.82 and 7.37 relative to a planar 3 cm² reference interface. Positional resistance mapping yielded an overall mean resistance of 47.80 ± 4.57 Ω, indicating acceptable electrical reproducibility across the structured conductive silicone interface. In addition, oscilloscope-based transient response analysis under a 5 V, 1 kHz square-wave input showed that the conductive silicone interface maintained the overall pulse waveform while showing a modest reduction in overshoot from 3.4 ± 0.1% to 2.7 ± 0.1%, with FFT traces used as qualitative waveform-monitoring displays. Formulation-dependent comparison further showed that increasing the silicone-rich fraction increased the measured resistance from 105 Ω to 145 Ω, whereas increasing conductive carbon loading reduced resistance but aggravated surface transfer. These results show that the conductive silicone interface functions not simply as a soft conductor, but as a volume-resistive, geometry-defined current-transfer medium whose behavior is governed by the coupled effects of conductive network formation, spike architecture, electrode-level resistance, and transient pulse response. This study provides a practical materials/interface design framework for spike-structured conductive silicone electrodes in wearable bioelectronic and electroceutical devices. Full article

A chronic wound is a wound that fails to progress through the normal stages of healing within a typical time frame, often remaining open and unhealed for more than 4 to 6 weeks. The delayed healing is often associated with comorbidities, and its clinical consequences have posed great concern to patients, caregivers, and researchers. The use of electrostimulation to enhance healing in chronic wounds has received attention in the last 20 years. Innovative wearable electroceutical devices are engineered to enhance the healing of chronic wounds while prioritizing patient convenience. These devices employ controlled micro-electrostimulation to reactivate endogenous bioelectric activities needed for cellular signaling. However, these devices and their mechanisms of electrostimulation have not been fully explored. In this systematic review, three databases with articles published between 2000 and 2023 were searched and screened using strict inclusion criteria while adhering to the PRISMA checklist. We identified direct, pulsed, and alternating electric currents as the primary modalities by electroceutical devices to deliver electrical stimulation in chronic wounds. Typical chronic wounds identified include diabetic foot ulcers, pressure ulcers, and diabetic venous ulcers. Additionally, a few materials crucial for chronic wound healing were reviewed, and recent devices in research were considered in this study. Various devices, including triboelectric and piezo-nanogenerators, were identified for their potential functionalities in generating electrical stimulation relevant to chronic wound applications. The literature lacked closed-loop electroceutical platforms for treatment and concurrent monitoring of wound healing. The analysis taken from this systematic review provides opportunities at the intersection of epidermal soft bioelectronics, wound care, and remote sensing. Full article

We aimed to reduce the recovery time for baseball pitchers from the established recovery period of four days to only one day. We designed a wearable and flexible arm sleeve composed of knitted nylon and a polyether–polyurea copolymer that has embedded proprietary dry electrodes that deliver a personalized microcurrent electron stream regimen as well as physiological motion sensors that provide real-time feedback for this electroceutical’s efficacy, positioning it as a revolutionary e-textile for enhancing and gauging sporting proficiency. Healables^® (Jerusalem, Israel) developed a noninvasive wearable device that docks onto its adjustable e-textile for team training and on-the-go and home-based improvement in terms of sports readiness, recovery, and performance. Full article

A flexible silver-zinc fabric-based primary battery that is biocompatible, conformable, and suitable for single-use wearable biomedical devices is reported. The planar battery was fabricated by screen printing silver/silver-chloride and zinc electrodes (14 mm × 8 mm) onto a silk substrate. A biologically relevant fluid, phosphate buffered saline was used as a liquid electrolyte for characterization. Cyclic voltammetry, electrochemical impedance spectroscopy, and current discharge properties at constant densities of 0.89 μA/cm², 8.93 μA/cm², and 89.29 μA/cm² were used to quantify battery performance. Nine cells were placed in series to generate a greater open circuit voltage (>6 V) relevant to previously reported biomedical applications. The nine-cell battery was evaluated for operation under mechanical strain due to likely placement on curved surfaces of the body in wearable applications. The nine-cell battery was discharged over 4 h at 8.93 μA/cm² in an unstrained condition. The mechanically strained battery when mounted to a mannequin to mimic anatomical curvature discharged up to 30 min faster. Additionally, the nine-cell battery was used in an in vitro wound model to power an electroceutical, showing promise towards practical use in active, corrosive, and potentially biohazardous environments. Full article

Currently, a large number of neurostimulators are commercially available for the treatment of drug-resistant diseases and as an alternative to pharmaceuticals. According to the current state of the art, such highly engineered electroceuticals require bulky battery units and necessitate the use of leads and extensions to connect the implantable electronic device to the stimulation electrodes. The battery life and the use of wired electrodes constrain the long-term use of such implantable systems. Furthermore, for therapeutic success and patient safety, it is of utmost importance to keep the stimulation current within a safe range. In this paper, we propose an implantable system design that consists of a low number of passive electronic components and does not require a battery. The stimulation parameters and power are transmitted inductively using an extracorporeal wearable transmitter at frequencies below 1 MHz. A simple circuit design approach is presented to achieve a closed-loop control of the stimulation current by exploiting the nonlinear properties of ferroelectric materials in ceramic capacitors. Twenty circuit topologies of series- and/or parallel-connected ceramic capacitors are investigated by measurement and are modeled in Mathcad. An approximately linear increase in the stimulation current, a stabilization of the stimulation current and an unstable state of the system were observed. In contrast to previous results, specific plateau ranges of the stimulation current can be set by the investigated circuit topologies. For further investigations, the consistency of the proposed model needs to be improved for higher induced voltage ranges. Full article