Optogenetic neuromuscular actuation of a miniature electronic biohybrid robot.

Neuronal control of skeletal muscle function is ubiquitous across species for locomotion and doing work. In particular, emergent behaviors of neurons in biohybrid neuromuscular systems can advance bioinspired locomotion research. Although recent studies have demonstrated that chemical or optogenetic stimulation of neurons can control muscular actuation through the neuromuscular junction (NMJ), the correlation between neuronal activities and resulting modulation in the muscle responses is less understood, hindering the engineering of high-level functional biohybrid systems.

Wireless, wearable elastography via mechano-acoustic wave sensing for ambulatory monitoring of tissue stiffness.

Assessing the mechanical properties of soft tissues holds broad clinical relevance. Advances in flexible electronics offer possibilities for wearable monitoring of tissue stiffness. However, existing technologies often rely on tethered setups or require frequent calibration, restricting their use in ambulatory environments.

Analysis and management of thermal loads generated in vivo by miniaturized optoelectronic implantable devices.

Miniaturized implantable optoelectronic technologies for in vivo biomedical applications are gaining interest, but require strict thermal management for safe operation. Here, we introduce a comprehensive framework combining analytical solutions and numerical modeling to estimate and manage thermal effects of optoelectronic devices. We propose Green's functions to analytically solve temperature distributions in tissue from a point source with coupled thermal-optical power, capturing the influence of critical tissue properties and spatiotemporal parameters.

Analytical solutions for light propagation of LED.

Analytical solutions of diffusion theory for light propagation in turbid media are essential for optical diagnostics and therapeutic applications, including cerebral oximetry, hemodynamic monitoring, and photostimulation. While existing solutions work reasonably well for collimated light sources-lasers and optical fibers-analytical solutions for LEDs remain missing, despite the growing use of LEDs in wearable and implantable bioelectronics. We present a method to solve the diffusion theory and derive analytical solutions for two biomedically relevant configurations: 1) surface-mounted LEDs on semi-infinite media (e.

Remote analysis and management of sweat biomarkers using a wearable microfluidic sticker in adult cystic fibrosis patients.

Sweat parameters such as volume and chloride concentration may offer invaluable clinical insights for people with CF (PwCF). Pilocarpine-induced sweat collection for chloridometry measurement is the gold standard for a CF diagnosis, but this technique is cumbersome and not suitable for remote settings or repeat measurements. We have previously reported the utility of a skin-interfaced microfluidic device (CF Patch) in conjunction with a smartphone image processing platform that enables real-time measurement of sweating rates and sodium chloride loss in laboratory and remote settings.

Minimally Invasive, Bioadaptive Multimodal Sensor Probe with Safe Deployment for Real-Time Acute Compartment Syndrome Diagnosis.

Acute Compartment Syndrome (ACS) is a serious medical condition that arises from increased pressure within osteofascial compartments, leading to impaired blood flow and potential tissue damage. Early and accurate diagnosis is critical for preventing permanent damage. Current methods rely largely on qualitative assessments with limited accuracy, and those that exploit invasive pressure measurements often prove inadequate.

Local optogenetic control of genome editing and tumorigenesis using wireless implantable optoelectronics.

Precise spatial regulation of site-specific DNA recombination (SSR) remains a challenge due to limited tunability of current platforms. Here, we present an optogenetic approach that overcome these limitations by employing engineered light-regulated recombinase E-LightR-Cre and tunable wireless implantable optoelectronic devices. E-LightR-Cre meets the key criteria for spatial regulation of SSR , showing no detectable activity in the dark, while demonstrating robust activation upon blue-light illumination.

Adaptive electronics for photovoltaic, photoluminescent and photometric methods in power harvesting for wireless wearable sensors.

The increasing demand for continuous, comprehensive physiological information captured by skin-interfaced wireless sensors is hindered by their relatively high-power consumption and the associated patient discomfort that can follow from the use of high capacity batteries. This paper presents an adaptive electronics platform and a tri-modal energy harvesting approach to reduce the need for battery power. Specifically, the schemes focus on sensors that involve light in their operation, through use of (i) photometric methods, where ambient light contributes directly to the measurement process, (ii) multijunction photovoltaic cells, where ambient light powers operation and/or charges an integrated battery, and (iii) photoluminescent packaging, where ambient light activates light-emitting species to enhance the first two schemes.

A skin-interfaced wireless wearable device and data analytics approach for sleep-stage and disorder detection.

Accurate identification of sleep stages and disorders is crucial for maintaining health, preventing chronic conditions, and improving diagnosis and treatment. Direct respiratory measurements, as key biomarkers, are missing in traditional wrist- or finger-worn wearables, which thus limit their precision in detection of sleep stages and sleep disorders. By contrast, this work introduces a simple, multimodal, skin-integrated, energy-efficient mechanoacoustic sensor capable of synchronized cardiac and respiratory measurements.

Bioresorbable, wireless dual stimulator for peripheral nerve regeneration.

Wireless bioresorbable electrical stimulators have broad potential as therapeutic implants. Such devices operate for a clinically relevant duration and then harmlessly dissolve, eliminating the need for surgical removal. A representative application is in treating peripheral nerve injuries through targeted stimulation at either proximal or distal sites, with operation for up to one week.

A compact, wireless system for continuous monitoring of breast milk expressed during breastfeeding.

Human milk is the ideal source of nutrition for infants. Most health organizations recommend direct breastfeeding from the first hour of life, extending throughout the first and second year. However, uncertainties regarding the volumes of milk ingested by the infant contribute to suboptimal rates of breastfeeding.

Soft, skin-interfaced wireless electrogoniometry systems for continuous monitoring of finger and wrist joints.

Continuous kinematic biofeedback during exercise interventions can lead to improved therapeutic outcomes in hand and wrist rehabilitation. Conventional methods for measuring joint kinematics typically allow only static measurements performed by specially trained therapists. This paper introduces skin-conformal, wearable wireless systems designed to continuously and accurately capture the angles of target joints, specifically in hand and wrist.

Implantable bioelectronics and wearable sensors for kidney health and disease.

Established clinical practices for monitoring kidney health and disease - including biopsy and serum biomarker analysis - suffer from practical limitations in monitoring frequency and lack adequate sensitivity for early disease detection. Engineering advances in biosensors have led to the development of wearable and implantable systems for monitoring of kidney health. Non-invasive microfluidic systems have demonstrated utility in the detection of kidney-relevant biomarkers, such as creatinine, urea and electrolytes in peripheral body fluids such as sweat, interstitial fluid, tears and saliva.

Wireless, battery-free, remote photoactivation of caged-morphine for photopharmacological pain modulation without side effects.

Chronic pain severely impairs physical, psychological, and cognitive functions. While opioid-based therapies can be effective, they are limited by tolerance, dependence, and adverse side effects, highlighting the need for safer alternatives. Recent advances in photopharmacology allow precise modulation of pain-related neuronal circuits, offering improved control and effectiveness.

An integrated microfluidic and fluorescence platform for probing in vivo neuropharmacology.

Neurotechnologies and genetic tools for dissecting neural circuit functions have advanced rapidly over the past decade although the development of complementary pharmacological methodologies has comparatively lagged. Understanding the precise pharmacological mechanisms of neuroactive compounds is critical for advancing basic neurobiology and neuropharmacology, as well as for developing more effective treatments for neurological and neuropsychiatric disorders. However, integrating modern tools for assessing neural activity in large-scale neural networks with spatially localized drug delivery remains a major challenge.

A non-contact wearable device for monitoring epidermal molecular flux.

Existing wearable technologies rely on physical coupling to the body to establish optical, fluidic, thermal and/or mechanical measurement interfaces. Here we present a class of wearable device platforms that instead relies on physical decoupling to define an enclosed chamber immediately adjacent to the skin surface. Streams of vapourized molecular substances that pass out of or into the skin alter the properties of the microclimate defined in this chamber in ways that can be precisely quantified using an integrated collection of wireless sensors.

Optogenetic activation of the gut-brain axis in freely moving mice using a fully implantable wireless battery-free device.

Considerable evidence suggests that the gut-brain axis can influence behavior. However, there has been a conspicuous lack of technology to provide targeted wireless activation of the gut-brain axis in conscious freely moving animals. We utilized a miniature fully implantable battery-free device to apply highly controlled optogenetic stimuli to the terminal region of gastrointestinal tract, in conscious freely moving mice.

Chronic, Battery-Free, Fully Implantable Multimodal Spinal Cord Stimulator for Pain Modulation in Small Animal Models.

Spinal cord stimulation (SCS) for chronic pain management is an invasive therapy involving surgical implantation of electrodes into spinal epidural space. While the clinical value and mechanistic action of the therapy is debated considerably in recent years, preclinical chronic studies employing rodent models can provide invaluable insights regarding the balance between efficacy and complications as well as mechanistic understanding of SCS therapy. However, current rodent compatible devices require tethered power delivery or bulky batteries, severely limiting the ability to probe long-term efficacy of SCS therapy.

Millimetre-scale bioresorbable optoelectronic systems for electrotherapy.

Temporary pacemakers are essential for the care of patients with short-lived bradycardia in post-operative and other settings. Conventional devices require invasive open-heart surgery or less invasive endovascular surgery, both of which are challenging for paediatric and adult patients. Other complications include risks of infections, lacerations and perforations of the myocardium, and of displacements of external power supplies and control systems.

Full freedom-of-motion actuators as advanced haptic interfaces.

The sense of touch conveys critical environmental information, facilitating object recognition, manipulation, and social interaction, and can be engineered through haptic actuators that stimulate cutaneous receptors. An unfulfilled challenge lies in haptic interface technologies that can engage all the various mechanoreceptors in a programmable, spatiotemporal fashion across large areas of the body. Here, we introduce a small-scale actuator technology that can impart omnidirectional, superimposable, dynamic forces to the surface of skin, as the basis for stimulating individual classes of mechanoreceptors or selected combinations of them.

Evaporative cooling for low-cost monitoring of flow of cerebrospinal fluid through shunts in patients with hydrocephalus.

Hydrocephalus, a neurological disorder caused by an abnormal accumulation of cerebrospinal fluid (CSF) in the brain, manifests in symptoms such as headaches, blurred vision, and balance issues. While ventriculoperitoneal shunting is a common treatment, it has high failure rates, especially in pediatric patients. Recent progress in continuous, non-invasive monitoring using skin-mounted sensors based on anemometric techniques and transient plane source methods offer significant promise.

Remote exercise-induced sweat chloride measurements using a wearable microfluidic sticker in cystic fibrosis patients.

Sweat parameters such as volume and chloride concentration may offer invaluable clinical insights for people with CF (PwCF). Pilocarpine-induced sweat collection for chloridometry measurement is the gold-standard for sweat chloride, but this technique is cumbersome and not suitable for remote settings. We have previously reported the utility of a skin-interfaced microfluidic device (CF Patch) in conjunction with a smartphone image processing platform that enables real-time measurement of sweating rates and sodium chloride loss in laboratory and remote settings.

Soft, wearable, microfluidic system for fluorometric analysis of loss of amino acids through eccrine sweat.

Amino acids are essential for protein synthesis and metabolic processes in support of homeostatic balance and healthy body functions. This study quantitatively investigates eccrine sweat as a significant channel for loss of amino acids during exercise, to improve an understanding of amino acid turnover and to provide feedback to users on the need for supplement intake. The measurement platform consists of a soft, skin-interfaced microfluidic system for real-time analysis of amino acid content in eccrine sweat.