Digitally-defined ultrathin transparent wireless sensor network for room-scale imperceptible ambient intelligence.

Wireless and battery-free radio-frequency (RF) sensors can be used to create physical spaces that ambiently sense and respond to human activities. Making such sensors ultra-flexible and transparent is important to preserve the aesthetics of living environments, accommodate daily activities, and functionally integrate with objects. However, existing RF sensors are unable to simultaneously achieve high transparency, flexibility, and the electrical conductivity required for remote room-scale operation.

Self-healing actuatable electroluminescent fibres.

Alternating-current electroluminescent fibres are promising candidates as light sources for smart textiles and soft machines. However, physical damage from daily use causes device deterioration or failure, making self-healable electroluminescent fibres attractive. In addition, soft robots could benefit from light-emitting combined with magnetically actuated functions.

Wireless sequential dual light delivery for programmed PDT in vivo.

Using photodynamic therapy (PDT) to treat deep-seated cancers is limited due to inefficient delivery of photosensitizers and low tissue penetration of light. Polymeric nanocarriers are widely used for photosensitizer delivery, while the self-quenching of the encapsulated photosensitizers would impair the PDT efficacy. Furthermore, the generated short-lived reactive oxygen spieces (ROS) can hardly diffuse out of nanocarriers, resulting in low PDT efficacy.

Harnessing metamaterials for efficient wireless power transfer for implantable medical devices.

Wireless power transfer (WPT) within the human body can enable long-lasting medical devices but poses notable challenges, including absorption by biological tissues and weak coupling between the transmitter (Tx) and receiver (Rx). In pursuit of more robust and efficient wireless power, various innovative strategies have emerged to optimize power transfer efficiency (PTE). One such groundbreaking approach stems from the incorporation of metamaterials, which have shown the potential to enhance the capabilities of conventional WPT systems.

Ambient health sensing on passive surfaces using metamaterials.

Ambient sensors can continuously and unobtrusively monitor a person's health and well-being in everyday settings. Among various sensing modalities, wireless radio-frequency sensors offer exceptional sensitivity, immunity to lighting conditions, and privacy advantages. However, existing wireless sensors are susceptible to environmental interference and unable to capture detailed information from multiple body sites.

A Magnetic Particle Imaging Approach for Minimally Invasive Imaging and Sensing With Implantable Bioelectronic Circuits.

Minimally-invasive and biocompatible implantable bioelectronic circuits are used for long-term monitoring of physiological processes in the body. However, there is a lack of methods that can cheaply and conveniently image the device within the body while simultaneously extracting sensor information. Magnetic Particle Imaging (MPI) with zero background signal, high contrast, and high sensitivity with quantitative images is ideal for this challenge because the magnetic signal is not absorbed with increasing tissue depth and incurs no radiation dose.

Ambient Cardiovascular Monitoring with Metamaterial Textile Sensors.

Contactless sensors embedded in the ambient environment have broad applications in unobtrusive, long-term health monitoring for preventative and personalized healthcare. Microwave radar sensors are an attractive candidate for ambient sensing due to their high sensitivity to physiological motions, ability to penetrate through obstacles and privacy-preserving properties, but practical applications in complex real-world environments have been limited because of challenges associated with background clutter and interference. In this work, we propose a thin and soft textile sensor based on microwave metamaterials that can be easily integrated into ordinary furniture for contactless ambient monitoring of multiple cardiovascular signals in a localized manner.

Frictionless multiphasic interface for near-ideal aero-elastic pressure sensing.

Conventional pressure sensors rely on solid sensing elements. Instead, inspired by the air entrapment phenomenon on the surfaces of submerged lotus leaves, we designed a pressure sensor that uses the solid-liquid-liquid-gas multiphasic interfaces and the trapped elastic air layer to modulate capacitance changes with pressure at the interfaces. By creating an ultraslippery interface and structuring the electrodes at the nanoscale and microscale, we achieve near-friction-free contact line motion and thus near-ideal pressure-sensing performance.

Implant-to-implant wireless networking with metamaterial textiles.

Implanted bioelectronic devices can form distributed networks capable of sensing health conditions and delivering therapy throughout the body. Current clinically-used approaches for wireless communication, however, do not support direct networking between implants because of signal losses from absorption and reflection by the body. As a result, existing examples of such networks rely on an external relay device that needs to be periodically recharged and constitutes a single point of failure.

Synergetic positivity of loss and noise in nonlinear non-Hermitian resonators.

Loss and noise are usually undesirable in electronics and optics, which are generally mitigated by separate ways in the cost of bulkiness and complexity. Recent studies of non-Hermitian systems have shown a positive role of loss in various loss-induced counterintuitive phenomena, while noise still remains a fundamental challenge in non-Hermitian systems particularly for sensing and lasing. Here, we simultaneously reverse the detrimental loss and noise and reveal their coordinated positive role in nonlinear non-Hermitian resonators.

Stochastic Exceptional Points for Noise-Assisted Sensing.

Noise is a fundamental challenge for sensors deployed in daily environments for ambient sensing, health monitoring, and wireless networking. Current strategies for noise mitigation rely primarily on reducing or removing noise. Here, we introduce stochastic exceptional points and show the utility to reverse the detrimental effect of noise.

Technology Roadmap for Flexible Sensors.

Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited.

Bioelectronic devices for light-based diagnostics and therapies.

Light has broad applications in medicine as a tool for diagnosis and therapy. Recent advances in optical technology and bioelectronics have opened opportunities for wearable, ingestible, and implantable devices that use light to continuously monitor health and precisely treat diseases. In this review, we discuss recent progress in the development and application of light-based bioelectronic devices.

Topographic design in wearable MXene sensors with in-sensor machine learning for full-body avatar reconstruction.

Wearable strain sensors that detect joint/muscle strain changes become prevalent at human-machine interfaces for full-body motion monitoring. However, most wearable devices cannot offer customizable opportunities to match the sensor characteristics with specific deformation ranges of joints/muscles, resulting in suboptimal performance. Adequate wearable strain sensor design is highly required to achieve user-designated working windows without sacrificing high sensitivity, accompanied with real-time data processing.

Needle-integrated ultrathin bioimpedance microsensor array for early detection of extravasation.

Extravasation is a common complication during intravenous therapy in which infused fluids leak into the surrounding tissues. Timely intervention can prevent severe adverse consequences, but early detection remains an unmet clinical need because existing sensors are not sensitive to leakage occurring in small volumes (< 200 μL) or at deep venipuncture sites. Here, an ultrathin bioimpedance microsensor array that can be integrated on intravenous needles for early and sensitive detection of extravasation is reported.

Wireless interfaces for brain neurotechnologies.

Wireless interfaces enable brain-implanted devices to remotely interact with the external world. They are critical components in modern research and clinical neurotechnologies and play a central role in determining their overall size, lifetime and functionality. Wireless interfaces use a wide range of modalities-including radio-frequency fields, acoustic waves and light-to transfer energy and data to and from an implanted device.

Electronic textiles for energy, sensing, and communication.

Electronic textiles (e-textiles) are fabrics that can perform electronic functions such as sensing, computation, display, and communication. They can enhance the functionality of clothing in a variety of convenient and unobtrusive ways, thus have garnered significant research and commercial interest in applications ranging from fashion to healthcare. Recent advances in materials science and electronics have given rise to variety of e-textile components, including sensors, energy harvesters, batteries, and antennas on flexible and breathable textiles substrates.

Digitally-embroidered liquid metal electronic textiles for wearable wireless systems.

Electronic textiles capable of sensing, powering, and communication can be used to non-intrusively monitor human health during daily life. However, achieving these functionalities with clothing is challenging because of limitations in the electronic performance, flexibility and robustness of the underlying materials, which must endure repeated mechanical, thermal and chemical stresses during daily use. Here, we demonstrate electronic textile systems with functionalities in near-field powering and communication created by digital embroidery of liquid metal fibers.

Wirelessly Activated Nanotherapeutics for In Vivo Programmable Photodynamic-Chemotherapy of Orthotopic Bladder Cancer.

Photochemical internalization (PCI) is a promising intervention using photodynamic therapy (PDT) to enhance the activity of chemotherapeutic drugs. However, current bladder cancer treatments involve high-dose chemotherapy and high-irradiance PDT which cause debilitating side effects. Moreover, low penetration of light and drugs in target tissues and cumbersome light delivery procedures hinder the clinical utility of PDT and chemotherapy combination for PCI.

Heterogeneous multi-compartmental DNA hydrogel particles prepared microfluidic assembly for lymphocyte-inspired precision medicine.

Lymphocytes play a vital role in immunosurveillance through sensing biomolecules and eliminating targeted invaders. Compared with conventional therapies that depend on drug loading, lymphocytes are advantageous as they are able to ensure self-regulated therapeutics. Here, novel multi-compartmental DNA hydrogel particles were synthesized using a microfluidic assembly for intelligent cancer treatment the logic-based control of siRNA release without external stimulation.

A wireless and battery-free wound infection sensor based on DNA hydrogel.

The confluence of wireless technology and biosensors offers the possibility to detect and manage medical conditions outside of clinical settings. Wound infections represent a major clinical challenge in which timely detection is critical for effective interventions, but this is currently hindered by the lack of a monitoring technology that can interface with wounds, detect pathogenic bacteria, and wirelessly transmit data. Here, we report a flexible, wireless, and battery-free sensor that provides smartphone-based detection of wound infection using a bacteria-responsive DNA hydrogel.

A wireless optoelectronic skin patch for light delivery and thermal monitoring.

Wearable optoelectronic devices can interface with the skin for applications in continuous health monitoring and light-based therapy. Measurement of the thermal effect of light on skin is often critical to track physiological parameters and control light delivery. However, accurate measurement of light-induced thermal effects is challenging because conventional sensors cannot be placed on the skin without obstructing light delivery.

Wirelessly operated bioelectronic sutures for the monitoring of deep surgical wounds.

Monitoring surgical wounds post-operatively is necessary to prevent infection, dehiscence and other complications. However, the monitoring of deep surgical sites is typically limited to indirect observations or to costly radiological investigations that often fail to detect complications before they become severe. Bioelectronic sensors could provide accurate and continuous monitoring from within the body, but the form factors of existing devices are not amenable to integration with sensitive wound tissues and to wireless data transmission.