Physically transient forms of electronics enable unique classes of technologies, ranging from bio... more Physically transient forms of electronics enable unique classes of technologies, ranging from biomedical implants that disappear through processes of bioresorption after serving a clinical need to internet-of-things devices that harmlessly dissolve into the environment following a relevant period of use. Here, we develop a sustainable manufacturing pathway, based on ultrafast pulsed laser ablation, that can support high-volume, cost-effective manipulation of a diverse collection of organic and inorganic materials, each designed to degrade by hydrolysis or enzymatic activity, into patterned, multi-layered architectures with high resolution and accurate overlay registration. The technology can operate in patterning, thinning and/or cutting modes with (ultra)thin eco/bioresorbable materials of different types of semiconductors, dielectrics, and conductors on flexible substrates. Component-level demonstrations span passive and active devices, including diodes and field-effect transistor...
Capabilities in continuous monitoring of key physiological parameters of disease have never been ... more Capabilities in continuous monitoring of key physiological parameters of disease have never been more important than in the context of the global COVID-19 pandemic. Soft, skin-mounted electronics that incorporate high-bandwidth, miniaturized motion sensors represent a powerful class of technology for digital, wireless measurements of mechano-acoustic (MA) signatures of both core vital signs (heart rate, respiratory rate, and temperature) and underexplored biomarkers (coughing count) with high fidelity and immunity to ambient noises. Here, we introduce an effort that integrates such an MA sensor, a cloud data infrastructure and data analytics approaches based on digital filtering and convolutional neural networks for comprehensive monitoring of COVID-19 infections in sick and healthy individuals in a population, both in the hospital and the home. This hardware/software system extracts diverse signatures of health status in an automated fashion from a single device and time series dat...
Highlights d Subdermal, wireless optogenetic platform for untethered neuronal control d Thin, fle... more Highlights d Subdermal, wireless optogenetic platform for untethered neuronal control d Thin, flexible devices for discrete spatio-temporal targeting of neural circuits d Low-cost, reliable NFC technology adaptable to most common behavioral contexts d NFC devices can be tailored for use with different wavelength opsins in vivo
Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces ... more Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient de...
Smartphone-compatible, wireless, battery-free hydration sensors can monitor skin diseases in any ... more Smartphone-compatible, wireless, battery-free hydration sensors can monitor skin diseases in any environment.
Proceedings of the National Academy of Sciences, 2021
Significance Continuous measurements of health status can be used to guide the care of patients a... more Significance Continuous measurements of health status can be used to guide the care of patients and to manage the spread of infectious diseases. Conventional monitoring systems cannot be deployed outside of hospital settings, and existing wearables cannot capture key respiratory biomarkers. This paper describes an automated wireless device and a data analysis approach that overcome these limitations, tailored for COVID-19 patients, frontline health care workers, and others at high risk. Vital signs and respiratory activity such as cough can reveal early signs of infection and quantitate responses to therapeutics. Long-term trials on COVID-19 patients in clinical and home settings demonstrate the translational value of this technology.
Wearable electronics with dual-sensing modalities enable artifact-free health monitoring through ... more Wearable electronics with dual-sensing modalities enable artifact-free health monitoring through differential detection.
Advanced technologies for controlled delivery of light to targeted locations in biological tissue... more Advanced technologies for controlled delivery of light to targeted locations in biological tissues are essential to neuroscience research that applies optogenetics in animal models. Fully implantable, miniaturized devices with wireless control and power-harvesting strategies offer an appealing set of attributes in this context, particularly for studies that are incompatible with conventional fiber-optic approaches or battery-powered head stages. Limited programmable control and narrow options in illumination profiles constrain the use of existing devices. The results reported here overcome these drawbacks via two platforms, both with real-time user programmability over multiple independent light sources, in head-mounted and back-mounted designs. Engineering studies of the optoelectronic and thermal properties of these systems define their capabilities and key design considerations. Neuroscience applications demonstrate that induction of interbrain neuronal synchrony in the medial prefrontal cortex shapes social interaction within groups of mice, highlighting the power of real-time subject-specific programmability of the wireless optogenetic platforms introduced here.
apabilities that follow from the intimate integration of high-performance electronic/optoelectron... more apabilities that follow from the intimate integration of high-performance electronic/optoelectronic systems with soft living tissues have the potential to serve as the basis for revolutionary approaches to diagnosing and treating diseases 1-5. A common vision is that a synergistic, bidirectional union of technology with biology will establish routes to improving health and prolonging life in ways that could complement those of traditional techniques. In all cases, the physical interfaces between these abiotic and biotic systems must enable soft mechanical coupling and functional optical/electrical/chemical exchange 6-8. Structural techniques based on surgical sutures, staples, cuffs or clips 9 have some utility but they induce damage to the tissues and the
Wireless, soft sensors continuously monitor pressure and temperature at the interface between a r... more Wireless, soft sensors continuously monitor pressure and temperature at the interface between a residual limb and a prosthesis.
Bioresorbable drug release platforms offer advanced treatment for hormone imbalances, malignant c... more Bioresorbable drug release platforms offer advanced treatment for hormone imbalances, malignant cancers, and diabetic conditions.
I n the United States, over 480,000 critically ill children receive care in ICUs each year, inclu... more I n the United States, over 480,000 critically ill children receive care in ICUs each year, including premature neonates weighing as little as 500 g 1-3. Continuous monitoring of vital signs is essential, yet existing technologies require the use of multiple electrodes and sensor interfaces attached to the skin with adhesives connected by wires to electronic processing systems that are often tethered to the wall. This system of hardware often frustrates both routine and specialized procedures in clinical care, ranging from therapeutic skin-to-skin contact with parents (that is, kangaroo care (KC)) to feeding, diaper changes and bathing 3. Furthermore, continuous monitoring of certain vital signs, such as blood pressure, demands additional wired tools, such as peripheral and umbilical arterial catheters 4 , which can induce other complications, including thrombus formation and blood-vessel occlusion, infection (for example sepsis), rupture, pseudoaneurysm, bleeding and death 5-7. A wireless system capable of non-invasive, continuous, accurate vital-signs monitoring has the potential to greatly enhance the safety and effectiveness of neonatal and pediatric critical care 8. A recent report by our group 9 describes a soft, skin-like electronic system designed to address these unmet clinical needs. Evaluation studies in the NICU confirm capabilities for clinically accurate measurements of heart rate (HR), blood oxygenation (SpO 2), temperature, respiration rate (RR) and pulse-wave velocity. This system, however, is limited by (1) the modest maximum operating distances (~30 cm) supported by wireless power transfer and data communication, (2) the mechanically fragile nature of the ultrathin, compliant mechanics designs, (3) the sufficient, but limited, range of measurement capabilities and (4) the demand for advanced device configurations, capable of fabrication in only specialized facilities with customized tools. The results reported here adapt and extend similar principles in soft electronics design, but in mechanically robust, manufacturable systems that circumvent these
Proceedings of the National Academy of Sciences, 2019
Significance Neuroscience studies using optogenetics have greatly improved our understanding of b... more Significance Neuroscience studies using optogenetics have greatly improved our understanding of brain circuits. Advances in the combined use of optogenetics and pharmacology to further probe important neurochemical signals has lagged, however, in large part due to the inconvenience of conventional cannulated approaches, as well as the difficulty in controlling, powering, and manufacturing optofluidic devices that are reliable and scalable for distribution to the neuroscience community. Here, we present a battery-free, wireless, lightweight optofluidic device that allows adjustable infusion rates, hands-free operation, and unlimited power supply, and is compatible with existing near-field communication (NFC) technology. We show that this device not only reproduces optogenetic and pharmacological experiments in vivo but, additionally, allows far greater freedom of movement in small animal models compared to existing, comparable platforms.
Sensitive sensing Neonatal care, particularly for premature babies, is complicated by the infants... more Sensitive sensing Neonatal care, particularly for premature babies, is complicated by the infants' fragility and by the need for a large number of tethered sensors to be attached to their tiny bodies. Chung et al. developed a pair of sensors that only require water to adhere to the skin and allow for untethered monitoring of key vital signs (see the Perspective by Guinsburg). On-board data processing allowed for efficient wireless near-field communication using standard protocols. The absence of cables makes it easier to handle the infants and allows for skin-to-skin contact between the babies and their parents or caregivers. Science , this issue p. eaau0780 ; see also p. 924
Recently developed classes of ultrasmall, fully implantable devices for optogenetic neuromodulati... more Recently developed classes of ultrasmall, fully implantable devices for optogenetic neuromodulation eliminate physical tethers associated with conventional setups and avoid bulky head-stages and batteries in alternative wireless technologies. The resulting systems enable completely untethered, battery-free operation for high fidelity behavioral studies that eliminate motion constraints and enable experiments in a range of environments and contexts (e.g. social interactions) that would be otherwise difficult or impossible to explore. These devices are, however, purely passive in their electronics design, thereby precluding any form of active control or programmability; independent operation of multiple devices or of multiple active components in a single device is impossible. This paper introduces a series of important concepts in integrated circuit and antenna design which, taken together, enable low power operation, energy efficient and position and angle independent wireless power harvesting with full user-programmability over individual devices or collections of them, in integrated platforms that have sizes and weights not significantly larger than those of previous, passive systems. The results qualitatively expand options in output stabilization, intensity control and multimodal operation, with broad potential applications in neuroscience research, with specific advances in precise dissection of neural circuit function during unconstrained behavioral studies.
Peripheral nerve injuries represent a significant problem in public health, constituting 2-5% of ... more Peripheral nerve injuries represent a significant problem in public health, constituting 2-5% of all trauma cases. For severe nerve injuries, even advanced forms of clinical intervention often lead to incomplete and unsatisfactory motor and/or sensory function. Numerous studies report the potential of pharmacological approaches (for example, growth factors, immunosuppressants) to accelerate and enhance nerve regeneration in rodent models. Unfortunately, few have had a positive impact in clinical practice. Direct intraoperative electrical stimulation of injured nerve tissue proximal to the site of repair has been demonstrated to enhance and accelerate functional recovery, suggesting a novel nonpharmacological, bioelectric form of therapy that could complement existing surgical approaches. A significant limitation of this technique is that existing protocols are constrained to intraoperative use and limited therapeutic benefits. Herein we introduce (i) a platform for wireless, program...
Thin, soft, skin-like sensors capable of precise, continuous measurements of physiological health... more Thin, soft, skin-like sensors capable of precise, continuous measurements of physiological health have broad potential relevance to clinical health care. Use of sensors distributed over a wide area for full-body, spatiotemporal mapping of physiological processes would be a considerable advance for this field. We introduce materials, device designs, wireless power delivery and communication strategies, and overall system architectures for skin-like, battery-free sensors of temperature and pressure that can be used across the entire body. Combined experimental and theoretical investigations of the sensor operation and the modes for wireless addressing define the key features of these systems. Studies with human subjects in clinical sleep laboratories and in adjustable hospital beds demonstrate functionality of the sensors, with potential implications for monitoring of circadian cycles and mitigating risks for pressure-induced skin ulcers.
The recent emergence of materials for electronic systems that are capable of programmable self-de... more The recent emergence of materials for electronic systems that are capable of programmable self-destruction and/or bio/eco-resorption creates the potential for important classes of devices that cannot be easily addressed using conventional technologies, ranging from temporary biomedical implants to enviromentally benign environmental monitors to hardware secure data systems. Although most previous demonstrations rely on wet chemistry to initiate transient processes of degradation/decomposition, options in "dry transient electronic systems" could expand the range of possible uses. The work presented here introduces materials and composite systems in which sublimation under ambient conditions leads to mechanical fragmentation and disintegration of active devices upon disappearance of a supporting substrate, encapsulation layer, interlayer dielectric and/or gate dielectric. Examples span arrays of transistors based on silicon nanomembranes with specialized device designs to solar cells adapted from commercial components.
Ultraviolet (UV) solar radiation is a leading cause of skin disease. Quantitative, continuous kno... more Ultraviolet (UV) solar radiation is a leading cause of skin disease. Quantitative, continuous knowledge of exposure levels can enhance awareness and lead to improved health outcomes. Devices that offer this type of measurement capability in formats that can seamlessly integrate with the skin are therefore of interest. This paper introduces materials, device designs, and data acquisition methods for a skin‐like, or “epidermal,” system that combines colorimetric and electronic function for precise dosimetry in the UV‐A and UV‐B regions of the spectrum, and for determination of instantaneous UV exposure levels and skin temperature. The colorimetric chemistry uses (4‐phenoxyphenyl)diphenylsulfonium triflate (PPDPS‐TF) with crystal violet lactone (CVL) and Congo red for UV‐A and UV‐B operation, respectively, when integrated with suitable optical filters. Coatings of poly(ethylene‐vinylacetate) (PEVA) protect the functional materials from sunscreen and other contamination. Quantitative in...
The advent of optogenetic tools has allowed unprecedented insights into the organization of neuro... more The advent of optogenetic tools has allowed unprecedented insights into the organization of neuronal networks. Although recently developed technologies have enabled implementation of optogenetics for studies of brain function in freely moving, untethered animals, wireless powering and device durability pose challenges in studies of spinal cord circuits where dynamic, multidimensional motions against hard and soft surrounding tissues can lead to device degradation. We demonstrate here a fully implantable optoelectronic device powered by near-field wireless communication (NFC) technology, with a thin and flexible open-architecture that provides excellent mechanical durability, robust sealing against biofluid penetration and fidelity in wireless activation, thereby allowing for long-term optical stimulation of the spinal cord without constraint on the natural behaviors of the animals. The system consists of a double-layer, rectangular-shaped magnetic coil antenna connected to a microsc...
Physically transient forms of electronics enable unique classes of technologies, ranging from bio... more Physically transient forms of electronics enable unique classes of technologies, ranging from biomedical implants that disappear through processes of bioresorption after serving a clinical need to internet-of-things devices that harmlessly dissolve into the environment following a relevant period of use. Here, we develop a sustainable manufacturing pathway, based on ultrafast pulsed laser ablation, that can support high-volume, cost-effective manipulation of a diverse collection of organic and inorganic materials, each designed to degrade by hydrolysis or enzymatic activity, into patterned, multi-layered architectures with high resolution and accurate overlay registration. The technology can operate in patterning, thinning and/or cutting modes with (ultra)thin eco/bioresorbable materials of different types of semiconductors, dielectrics, and conductors on flexible substrates. Component-level demonstrations span passive and active devices, including diodes and field-effect transistor...
Capabilities in continuous monitoring of key physiological parameters of disease have never been ... more Capabilities in continuous monitoring of key physiological parameters of disease have never been more important than in the context of the global COVID-19 pandemic. Soft, skin-mounted electronics that incorporate high-bandwidth, miniaturized motion sensors represent a powerful class of technology for digital, wireless measurements of mechano-acoustic (MA) signatures of both core vital signs (heart rate, respiratory rate, and temperature) and underexplored biomarkers (coughing count) with high fidelity and immunity to ambient noises. Here, we introduce an effort that integrates such an MA sensor, a cloud data infrastructure and data analytics approaches based on digital filtering and convolutional neural networks for comprehensive monitoring of COVID-19 infections in sick and healthy individuals in a population, both in the hospital and the home. This hardware/software system extracts diverse signatures of health status in an automated fashion from a single device and time series dat...
Highlights d Subdermal, wireless optogenetic platform for untethered neuronal control d Thin, fle... more Highlights d Subdermal, wireless optogenetic platform for untethered neuronal control d Thin, flexible devices for discrete spatio-temporal targeting of neural circuits d Low-cost, reliable NFC technology adaptable to most common behavioral contexts d NFC devices can be tailored for use with different wavelength opsins in vivo
Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces ... more Capabilities for continuous monitoring of pressures and temperatures at critical skin interfaces can help to guide care strategies that minimize the potential for pressure injuries in hospitalized patients or in individuals confined to the bed. This paper introduces a soft, skin-mountable class of sensor system for this purpose. The design includes a pressure-responsive element based on membrane deflection and a battery-free, wireless mode of operation capable of multi-site measurements at strategic locations across the body. Such devices yield continuous, simultaneous readings of pressure and temperature in a sequential readout scheme from a pair of primary antennas mounted under the bedding and connected to a wireless reader and a multiplexer located at the bedside. Experimental evaluation of the sensor and the complete system includes benchtop measurements and numerical simulations of the key features. Clinical trials involving two hemiplegic patients and a tetraplegic patient de...
Smartphone-compatible, wireless, battery-free hydration sensors can monitor skin diseases in any ... more Smartphone-compatible, wireless, battery-free hydration sensors can monitor skin diseases in any environment.
Proceedings of the National Academy of Sciences, 2021
Significance Continuous measurements of health status can be used to guide the care of patients a... more Significance Continuous measurements of health status can be used to guide the care of patients and to manage the spread of infectious diseases. Conventional monitoring systems cannot be deployed outside of hospital settings, and existing wearables cannot capture key respiratory biomarkers. This paper describes an automated wireless device and a data analysis approach that overcome these limitations, tailored for COVID-19 patients, frontline health care workers, and others at high risk. Vital signs and respiratory activity such as cough can reveal early signs of infection and quantitate responses to therapeutics. Long-term trials on COVID-19 patients in clinical and home settings demonstrate the translational value of this technology.
Wearable electronics with dual-sensing modalities enable artifact-free health monitoring through ... more Wearable electronics with dual-sensing modalities enable artifact-free health monitoring through differential detection.
Advanced technologies for controlled delivery of light to targeted locations in biological tissue... more Advanced technologies for controlled delivery of light to targeted locations in biological tissues are essential to neuroscience research that applies optogenetics in animal models. Fully implantable, miniaturized devices with wireless control and power-harvesting strategies offer an appealing set of attributes in this context, particularly for studies that are incompatible with conventional fiber-optic approaches or battery-powered head stages. Limited programmable control and narrow options in illumination profiles constrain the use of existing devices. The results reported here overcome these drawbacks via two platforms, both with real-time user programmability over multiple independent light sources, in head-mounted and back-mounted designs. Engineering studies of the optoelectronic and thermal properties of these systems define their capabilities and key design considerations. Neuroscience applications demonstrate that induction of interbrain neuronal synchrony in the medial prefrontal cortex shapes social interaction within groups of mice, highlighting the power of real-time subject-specific programmability of the wireless optogenetic platforms introduced here.
apabilities that follow from the intimate integration of high-performance electronic/optoelectron... more apabilities that follow from the intimate integration of high-performance electronic/optoelectronic systems with soft living tissues have the potential to serve as the basis for revolutionary approaches to diagnosing and treating diseases 1-5. A common vision is that a synergistic, bidirectional union of technology with biology will establish routes to improving health and prolonging life in ways that could complement those of traditional techniques. In all cases, the physical interfaces between these abiotic and biotic systems must enable soft mechanical coupling and functional optical/electrical/chemical exchange 6-8. Structural techniques based on surgical sutures, staples, cuffs or clips 9 have some utility but they induce damage to the tissues and the
Wireless, soft sensors continuously monitor pressure and temperature at the interface between a r... more Wireless, soft sensors continuously monitor pressure and temperature at the interface between a residual limb and a prosthesis.
Bioresorbable drug release platforms offer advanced treatment for hormone imbalances, malignant c... more Bioresorbable drug release platforms offer advanced treatment for hormone imbalances, malignant cancers, and diabetic conditions.
I n the United States, over 480,000 critically ill children receive care in ICUs each year, inclu... more I n the United States, over 480,000 critically ill children receive care in ICUs each year, including premature neonates weighing as little as 500 g 1-3. Continuous monitoring of vital signs is essential, yet existing technologies require the use of multiple electrodes and sensor interfaces attached to the skin with adhesives connected by wires to electronic processing systems that are often tethered to the wall. This system of hardware often frustrates both routine and specialized procedures in clinical care, ranging from therapeutic skin-to-skin contact with parents (that is, kangaroo care (KC)) to feeding, diaper changes and bathing 3. Furthermore, continuous monitoring of certain vital signs, such as blood pressure, demands additional wired tools, such as peripheral and umbilical arterial catheters 4 , which can induce other complications, including thrombus formation and blood-vessel occlusion, infection (for example sepsis), rupture, pseudoaneurysm, bleeding and death 5-7. A wireless system capable of non-invasive, continuous, accurate vital-signs monitoring has the potential to greatly enhance the safety and effectiveness of neonatal and pediatric critical care 8. A recent report by our group 9 describes a soft, skin-like electronic system designed to address these unmet clinical needs. Evaluation studies in the NICU confirm capabilities for clinically accurate measurements of heart rate (HR), blood oxygenation (SpO 2), temperature, respiration rate (RR) and pulse-wave velocity. This system, however, is limited by (1) the modest maximum operating distances (~30 cm) supported by wireless power transfer and data communication, (2) the mechanically fragile nature of the ultrathin, compliant mechanics designs, (3) the sufficient, but limited, range of measurement capabilities and (4) the demand for advanced device configurations, capable of fabrication in only specialized facilities with customized tools. The results reported here adapt and extend similar principles in soft electronics design, but in mechanically robust, manufacturable systems that circumvent these
Proceedings of the National Academy of Sciences, 2019
Significance Neuroscience studies using optogenetics have greatly improved our understanding of b... more Significance Neuroscience studies using optogenetics have greatly improved our understanding of brain circuits. Advances in the combined use of optogenetics and pharmacology to further probe important neurochemical signals has lagged, however, in large part due to the inconvenience of conventional cannulated approaches, as well as the difficulty in controlling, powering, and manufacturing optofluidic devices that are reliable and scalable for distribution to the neuroscience community. Here, we present a battery-free, wireless, lightweight optofluidic device that allows adjustable infusion rates, hands-free operation, and unlimited power supply, and is compatible with existing near-field communication (NFC) technology. We show that this device not only reproduces optogenetic and pharmacological experiments in vivo but, additionally, allows far greater freedom of movement in small animal models compared to existing, comparable platforms.
Sensitive sensing Neonatal care, particularly for premature babies, is complicated by the infants... more Sensitive sensing Neonatal care, particularly for premature babies, is complicated by the infants' fragility and by the need for a large number of tethered sensors to be attached to their tiny bodies. Chung et al. developed a pair of sensors that only require water to adhere to the skin and allow for untethered monitoring of key vital signs (see the Perspective by Guinsburg). On-board data processing allowed for efficient wireless near-field communication using standard protocols. The absence of cables makes it easier to handle the infants and allows for skin-to-skin contact between the babies and their parents or caregivers. Science , this issue p. eaau0780 ; see also p. 924
Recently developed classes of ultrasmall, fully implantable devices for optogenetic neuromodulati... more Recently developed classes of ultrasmall, fully implantable devices for optogenetic neuromodulation eliminate physical tethers associated with conventional setups and avoid bulky head-stages and batteries in alternative wireless technologies. The resulting systems enable completely untethered, battery-free operation for high fidelity behavioral studies that eliminate motion constraints and enable experiments in a range of environments and contexts (e.g. social interactions) that would be otherwise difficult or impossible to explore. These devices are, however, purely passive in their electronics design, thereby precluding any form of active control or programmability; independent operation of multiple devices or of multiple active components in a single device is impossible. This paper introduces a series of important concepts in integrated circuit and antenna design which, taken together, enable low power operation, energy efficient and position and angle independent wireless power harvesting with full user-programmability over individual devices or collections of them, in integrated platforms that have sizes and weights not significantly larger than those of previous, passive systems. The results qualitatively expand options in output stabilization, intensity control and multimodal operation, with broad potential applications in neuroscience research, with specific advances in precise dissection of neural circuit function during unconstrained behavioral studies.
Peripheral nerve injuries represent a significant problem in public health, constituting 2-5% of ... more Peripheral nerve injuries represent a significant problem in public health, constituting 2-5% of all trauma cases. For severe nerve injuries, even advanced forms of clinical intervention often lead to incomplete and unsatisfactory motor and/or sensory function. Numerous studies report the potential of pharmacological approaches (for example, growth factors, immunosuppressants) to accelerate and enhance nerve regeneration in rodent models. Unfortunately, few have had a positive impact in clinical practice. Direct intraoperative electrical stimulation of injured nerve tissue proximal to the site of repair has been demonstrated to enhance and accelerate functional recovery, suggesting a novel nonpharmacological, bioelectric form of therapy that could complement existing surgical approaches. A significant limitation of this technique is that existing protocols are constrained to intraoperative use and limited therapeutic benefits. Herein we introduce (i) a platform for wireless, program...
Thin, soft, skin-like sensors capable of precise, continuous measurements of physiological health... more Thin, soft, skin-like sensors capable of precise, continuous measurements of physiological health have broad potential relevance to clinical health care. Use of sensors distributed over a wide area for full-body, spatiotemporal mapping of physiological processes would be a considerable advance for this field. We introduce materials, device designs, wireless power delivery and communication strategies, and overall system architectures for skin-like, battery-free sensors of temperature and pressure that can be used across the entire body. Combined experimental and theoretical investigations of the sensor operation and the modes for wireless addressing define the key features of these systems. Studies with human subjects in clinical sleep laboratories and in adjustable hospital beds demonstrate functionality of the sensors, with potential implications for monitoring of circadian cycles and mitigating risks for pressure-induced skin ulcers.
The recent emergence of materials for electronic systems that are capable of programmable self-de... more The recent emergence of materials for electronic systems that are capable of programmable self-destruction and/or bio/eco-resorption creates the potential for important classes of devices that cannot be easily addressed using conventional technologies, ranging from temporary biomedical implants to enviromentally benign environmental monitors to hardware secure data systems. Although most previous demonstrations rely on wet chemistry to initiate transient processes of degradation/decomposition, options in "dry transient electronic systems" could expand the range of possible uses. The work presented here introduces materials and composite systems in which sublimation under ambient conditions leads to mechanical fragmentation and disintegration of active devices upon disappearance of a supporting substrate, encapsulation layer, interlayer dielectric and/or gate dielectric. Examples span arrays of transistors based on silicon nanomembranes with specialized device designs to solar cells adapted from commercial components.
Ultraviolet (UV) solar radiation is a leading cause of skin disease. Quantitative, continuous kno... more Ultraviolet (UV) solar radiation is a leading cause of skin disease. Quantitative, continuous knowledge of exposure levels can enhance awareness and lead to improved health outcomes. Devices that offer this type of measurement capability in formats that can seamlessly integrate with the skin are therefore of interest. This paper introduces materials, device designs, and data acquisition methods for a skin‐like, or “epidermal,” system that combines colorimetric and electronic function for precise dosimetry in the UV‐A and UV‐B regions of the spectrum, and for determination of instantaneous UV exposure levels and skin temperature. The colorimetric chemistry uses (4‐phenoxyphenyl)diphenylsulfonium triflate (PPDPS‐TF) with crystal violet lactone (CVL) and Congo red for UV‐A and UV‐B operation, respectively, when integrated with suitable optical filters. Coatings of poly(ethylene‐vinylacetate) (PEVA) protect the functional materials from sunscreen and other contamination. Quantitative in...
The advent of optogenetic tools has allowed unprecedented insights into the organization of neuro... more The advent of optogenetic tools has allowed unprecedented insights into the organization of neuronal networks. Although recently developed technologies have enabled implementation of optogenetics for studies of brain function in freely moving, untethered animals, wireless powering and device durability pose challenges in studies of spinal cord circuits where dynamic, multidimensional motions against hard and soft surrounding tissues can lead to device degradation. We demonstrate here a fully implantable optoelectronic device powered by near-field wireless communication (NFC) technology, with a thin and flexible open-architecture that provides excellent mechanical durability, robust sealing against biofluid penetration and fidelity in wireless activation, thereby allowing for long-term optical stimulation of the spinal cord without constraint on the natural behaviors of the animals. The system consists of a double-layer, rectangular-shaped magnetic coil antenna connected to a microsc...
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Papers by Tony Banks