Bioelectronic devices

A wearable electrochemical biosensor can continuously detect, in sweat during physical exercise and at rest, trace levels of multiple metabolites and nutrients, including all essential amino acids and vitamins.

Multifilament surgical sutures functionalized with a conductive polymer and incorporating pledgets with capacitive sensors operated via radiofrequency identification can be used to monitor physicochemical states of deep surgical sites.

A prototype skin-conformal ultrasonic phased array enables the monitoring of physiological signals from deep tissues, as shown for the measurements of cardiac Doppler waveforms and central and cerebral blood flows.

Electromagnetic devices involving a vibratory actuator and a soft strain-sensing sheet can dynamically measure the Young’s modulus of skin and of other soft biological tissues at depths of millimetres.

Large-scale single-neuron recordings from hearing-impaired gerbils show that compression and amplification algorithms used in hearing aids restore the sensitivity of neural responses to speech, but not their selectivity.

A soft and transparent contact lens can be used to wirelessly monitor intraocular pressure quantitatively in humans.

A skin-worn device that simultaneously monitors blood pressure and heart rate via ultrasonic transducers and multiple biomarkers via electrochemical sensors captures physiological effects of food intake and exercise in human volunteers.

Customized soft electrode arrays that are well adjusted to specific anatomical environments, functions and experimental models can be rapidly prototyped via the robotically controlled deposition of conductive inks and insulating inks.

An integrated system consisting of conformable piezoelectric devices, three-dimensional digital image correlation, multiphysics modelling and real-time classification algorithms predicts facial kinematics and decodes facial deformations.

Soft multilayer electronic arrays on endocardial balloon catheters allow for multiplexed high-density spatiotemporal sensing and actuation, as shown in perfused ex vivo hearts.

A wireless device designed to be conformally placed on the suprasternal notch can continuously provide real-time information of essential vital signs as well as talking time, swallow counts and sleep patterns.

Functionalized multi-walled carbon nanotubes twisted into helical fibre bundles that mimic the hierarchical structure of muscle can be used for the long-term monitoring of multiple disease biomarkers in vivo.

An electronic interface with 4,096 electrodes can intracellularly record postsynaptic potentials and action potentials from thousands of connected mammalian neurons in vitro.

Body-scale epidermal electronic interfaces for electrophysiological recordings enable the control of a transhumeral prosthesis, long-term electroencephalography, and simultaneous electroencephalography and structural and functional MRI.

A battery-free implantable pressure sensor made entirely of biodegradable materials and based on fringe-field capacitor technology can wirelessly measure arterial blood flow in live rats.

Conductive and elastic hydrogel-based microelectronic arrays with high current-injection density and low interfacial impedance with tissue enable the localized low-voltage electrical stimulation of the sciatic nerve in live mice.

A closed-loop and wireless 128-channel neuromodulation device enables electrical stimulation as well as artefact-free long-term recording of local field potentials in the brain of an untethered non-human primate.

Implantable inductively coupled resonant circuits that change their properties in response to electrical or photonic cues and are detectable in magnetic resonance imaging enable the remote sensing of bioluminescence in rodent brains.

Bioresorbable pressure sensors with significantly improved operational lifetimes, as exemplified via the monitoring of intracranial pressure in rats for over 25 days, can be similarly accurate to analogous non-resorbable clinical devices.

An ultrasonic and stretchable device conformal to the skin that captures blood pressure waveforms at deeply embedded arterial and venous sites enables the continuous monitoring of cardiovascular events.

An implantable, wirelessly powered optoelectronic device that adheres to tissue for the delivery of low-dose, long-term photodynamic therapy leads to significant antitumour effects in mice with intradermally transplanted tumours.

The location of microdevices in the body of anaesthetized mice can be retrieved with sub-millimetre precision by adopting principles from nuclear magnetic resonance.

An ingestible, flexible piezoelectric sensor that senses mechanical deformations in the gastric cavity allows for the monitoring of ingestion states in the gastrointestinal tract of pigs.

A biocompatible, energy-harvesting electrochemical cell delivers power to a wireless sensor for an average of 6.1 days of temperature measurements in the gastrointestinal tract of pigs.

A phased electromagnetic surface that conforms to the body surface can regulate cardiac rhythm in a porcine model through the wireless transmission of power to miniaturized semiconductor devices implanted at depths of over 4 cm.

Capacitive coupling between tissue and flexible integrated electronics through a sealing dielectric layer facilitates long-term electrophysiology measurements, as demonstrated in ex vivo Langendorff heart models.

Deep surgical wounds can be monitored via conductive multifilament surgical sutures incorporating ‘sensing pledgets’ bearing capacitive sensors operated via harmonic radiofrequency identification.

The elastic modulus of the superficial and deep layers of the skin can be dynamically measured via wearable conformal electromagnetic devices consisting of a vibratory actuator and a soft strain-sensing sheet.

Organic electrochemical transistors functionalized with antigen-specific nanobodies can rapidly and specifically detect antigens at attomolar-to-nanomolar levels in bodily fluids.

An analysis of the neural coding of speech sounds in anaesthetized gerbils shows that sound-processing algorithms used by hearing aids can degrade the wearer’s ability to discriminate sounds.

The integration and miniaturization of components in electronic and photonic devices for interfacing with neural tissue allow for ever more precise neural recording and stimulation.

Functionalized flexible helical bundles of carbon nanotubes serve as electrochemical sensors for long-term in vivo monitoring of disease biomarkers.

An electrode array implanted into the optic nerve of rabbits selectively activates discrete regions of the primary visual cortex.

Large-area electrode arrays for epidermal electrophysiology offer new possibilities for the control of prosthetic devices and the monitoring of brain function.

Implantable sensors and electrodes that take advantage of new materials, device designs and fabrication strategies enable new and improved biomedical applications.

A soft implant wirelessly senses arterial blood flow post-surgery before being gradually resorbed.

Stretchable conductive hydrogels make microelectrode arrays that better interface with tissue.

A wirelessly powered optoelectronic device that adheres to internal tissue facilitates the application of low-dose, long-term photodynamic cancer therapy.

A miniaturized 128-electrode brain implant enables wireless closed-loop neuromodulation with artefact cancellation in a non-human primate.

A microdevice implanted in deep tissue can measure electromagnetic signals and convert them to magnetic-resonance-imaging-detectable signals.

A wearable ultrasound patch enables the continuous monitoring of cardiovascular performance outside the intensive care unit.

Microchips embedding a magnetic sensor and a radiofrequency transmitter can be localized in the body of a mouse at submillimetre resolution when under a magnetic field.

Flexible piezoelectric sensors can detect mechanical deformations in the gastrointestinal tract of ambulating pigs and simultaneously harvest energy from it.

A biosensing device that harvests energy from fluids in the gut is able to wirelessly transmit measurements from the gastrointestinal tract of pigs for over six days.

Phased-array antennas that conform to body surfaces efficiently transfer electromagnetic energy to miniaturized semiconductor devices implanted in pigs.

A silicon dioxide passivation layer dramatically lengthens the operational lifetime of flexible electronic arrays for cardiac electrophysiology.

Soft integrated electronics packaged with miniaturized modules for wireless power and data transfer are opening up new opportunities for long-term health monitoring and therapy.

Advances in materials science and engineering enable ever-smaller and more reliable bioelectronic devices.