Over the past decade, the area of stretchable inorganic electronics has evolved very rapidly, in part because the results have opened up a series of unprecedented applications with broad interest and ...potential for impact, especially in bio‐integrated systems. Low modulus mechanics and the ability to accommodate extreme mechanical deformations, especially high levels of stretching, represent key defining characteristics. Most existing studies exploit structural material designs to achieve these properties, through the integration of hard inorganic electronic components configured into strategic 2D/3D geometries onto patterned soft substrates. The diverse structural geometries developed for stretchable inorganic electronics are summarized, covering the designs of functional devices and soft substrates, with a focus on fundamental principles, design approaches, and system demonstrations. Strategies that allow spatial integration of 3D stretchable device layouts are also highlighted. Finally, perspectives on the remaining challenges and open opportunities are provided.
Diverse material structures for stretchable inorganic electronics are summarized, covering both functional devices and soft substrates, with a focus on the fundamental principles, design approaches, and system demonstrations. Strategies that allow spatial integration of 3D stretchable device configurations are also highlighted. Finally, perspectives on remaining challenges and open opportunities are provided.
We describe recent advances in soft electronic interface technologies for neuroscience research. Here, low modulus materials and/or compliant mechanical structures enable modes of soft, conformal ...integration and minimally invasive operation that would be difficult or impossible to achieve using conventional approaches. We begin by summarizing progress in electrodes and associated electronics for signal amplification and multiplexed readout. Examples in large-area, surface conformal electrode arrays and flexible, multifunctional depth-penetrating probes illustrate the power of these concepts. A concluding section highlights areas of opportunity in the further development and application of these technologies.
In this issue, Jeong et al. review recent advances in soft electronic interface technologies for neuroscience research, describing progress in electrodes and associated integrated electronics for signal amplification and multiplexed readout and highlighting opportunities for the further development and use of these technologies.
Materials and Mechanics for Stretchable Electronics Rogers, John A.; Someya, Takao; Huang, Yonggang
Science (American Association for the Advancement of Science),
03/2010, Volume:
327, Issue:
5973
Journal Article
Peer reviewed
Recent advances in mechanics and materials provide routes to integrated circuits that can offer the electrical properties of conventional, rigid wafer-based technologies but with the ability to be ...stretched, compressed, twisted, bent, and deformed into arbitrary shapes. Inorganic and organic electronic materials in microstructured and nanostructured forms, intimately integrated with elastomeric substrates, offer particularly attractive characteristics, with realistic pathways to sophisticated embodiments. Here, we review these strategies and describe applications of them in systems ranging from electronic eyeball cameras to deformable light-emitting displays. We conclude with some perspectives on routes to commercialization, new device opportunities, and remaining challenges for research.
Ultrathin films of single‐walled carbon nanotubes (SWNTs) represent an attractive, emerging class of material, with properties that can approach the exceptional electrical, mechanical, and optical ...characteristics of individual SWNTs, in a format that, unlike isolated tubes, is readily suitable for scalable integration into devices. These features suggest the potential for realistic applications as conducting or semiconducting layers in diverse types of electronic, optoelectronic and sensor systems. This article reviews recent advances in assembly techniques for forming such films, modeling and experimental work that reveals their collective properties, and engineering aspects of implementation in sensors and in electronic devices and circuits with various levels of complexity. A concluding discussion provides some perspectives on possibilities for future work in fundamental and applied aspects.
Thin films of single‐walled carbon nanotubes (SWNTs) can serve as active materials for various electronic and sensor systems, ranging from flexible, transparent circuits to chemical detectors to radio frequency analog devices. The image shows a flexible SWNT thin film digital logic circuit wrapped around a cylindrical support (background) and electrical characteristics of a representative transistor (foreground). This review describes progress in this emerging field.
Dual-functioning displays, which can simultaneously transmit and receive information and energy through visible light, would enable enhanced user interfaces and device-to-device interactivity. We ...demonstrate that double heterojunctions designed into colloidal semiconductor nanorods allow both efficient photocurrent generation through a photovoltaic response and electroluminescence within a single device. These dual-functioning, all-solution-processed double-heterojunction nanorod light-responsive light-emitting diodes open feasible routes to a variety of advanced applications, from touchless interactive screens to energy harvesting and scavenging displays and massively parallel display-to-display data communication.
•Cellular-scale optoelectronics for wireless optogenetics and photometry.•Wireless, battery-free subdermal implants with multimodal energy harvesting.•Soft, injectable microfluidic systems for ...programmed pharmacological delivery.
Recently developed classes of ultraminiaturized wireless devices provide powerful capabilities in neuroscience research, as implantable light sources for simulation/inhibition via optogenetics, as integrated microfluidic systems for programmed pharmacological delivery and as multimodal sensors for physiological measurements. These platforms leverage basic advances in biocompatible materials, semiconductor device designs and systems engineering concepts to afford modes of operation that are qualitatively distinct from those of conventional approaches that tether animals to external hardware by means of optical fibers, electrical cables and/or fluidic tubing. Neuroscience studies that exploit the unique features of these technologies enable insights into neural function through targeted stimulation, inhibition and recording, with spatially and genetically precise manipulation of neural circuit activity. Experimental possibilities include studies in naturalistic, three dimensional environments, investigations of pair-wise or group related social interactions and many other scenarios of interest that cannot be addressed using traditional hardware.
Conspectus Recent advances in materials chemistry establish the foundations for unusual classes of electronic systems, characterized by their ability to fully or partially dissolve, disintegrate, or ...otherwise physically or chemically decompose in a controlled fashion after some defined period of stable operation. Such types of “transient” technologies may enable consumer gadgets that minimize waste streams associated with disposal, implantable sensors that disappear harmlessly in the body, and hardware-secure platforms that prevent unwanted recovery of sensitive data. This second area of opportunity, sometimes referred to as bioresorbable electronics, is of particular interest due to its ability to provide diagnostic or therapeutic function in a manner that can enhance or monitor transient biological processes, such as wound healing, while bypassing risks associated with extended device load on the body or with secondary surgical procedures for removal. Early chemistry research established sets of bioresorbable materials for substrates, encapsulation layers, and dielectrics, along with several options in organic and bio-organic semiconductors. The subsequent realization that nanoscale forms of device-grade monocrystalline silicon, such as silicon nanomembranes (m-Si NMs, or Si NMs) undergo hydrolysis in biofluids to yield biocompatible byproducts over biologically relevant time scales advanced the field by providing immediate routes to high performance operation and versatile, sophisticated levels of function. When combined with bioresorbable conductors, dielectrics, substrates, and encapsulation layers, Si NMs provide the basis for a broad, general class of bioresorbable electronics. Other properties of Si, such as its piezoresistivity and photovoltaic properties, allow other types of bioresorbable devices such as solar cells, strain gauges, pH sensors, and photodetectors. The most advanced bioresorbable devices now exist as complete systems with successful demonstrations of clinically relevant modes of operation in animal models. This Account highlights the foundational materials concepts for this area of technology, starting with the dissolution chemistry and reaction kinetics associated with hydrolysis of Si NMs as a function of temperature, pH, and ion and protein concentration. A following discussion focuses on key supporting materials, including a range of dielectrics, metals, and substrates. As comparatively low performance alternatives to Si NMs, bioresorbable organic semiconductors are also presented, where interest derives from their intrinsic flexibility, low-temperature processability, and ease of chemical modification. Representative examples of encapsulation materials and strategies in passive and active control of device lifetime are then discussed, with various device illustrations. A final section outlines bioresorbable electronics for sensing of various biophysical parameters, monitoring electrophysiological activity, and delivering drugs in a programmed manner. Fundamental research in chemistry remains essential to the development of this emerging field, where continued advances will increase the range of possibilities in sensing, actuation, and power harvesting. Materials for encapsulation layers that can delay water-diffusion and dissolution of active electronics in passively or actively triggered modes are particularly important in addressing areas of opportunity in clinical medicine, and in secure systems for envisioned military and industrial uses. The deep scientific content and the broad range of application opportunities suggest that research in transient electronic materials will remain a growing area of interest to the chemistry community.
Combined advances in material science, mechanical engineering, and electrical engineering form the foundations of thin, soft electronic/optoelectronic platforms that have unique capabilities in ...wireless monitoring and control of various biological processes in cells, tissues, and organs. Miniaturized, stretchable antennas represent an essential link between such devices and external systems for control, power delivery, data processing, and/or communication. Applications typically involve a demanding set of considerations in performance, size, and stretchability. Some of the most effective strategies rely on unusual materials such as liquid metals, nanowires, and woven textiles or on optimally configured 2D/3D structures such as serpentines and helical coils of conventional materials. In the best cases, the performance metrics of small, stretchable, radio frequency (RF) antennas realized using these strategies compare favorably to those of traditional devices. Examples range from dipole, monopole, and patch antennas for far‐field RF operation, to magnetic loop antennas for near‐field communication (NFC), where the key parameters include operating frequency, Q factor, radiation pattern, and reflection coefficient S11 across a range of mechanical deformations and cyclic loads. Despite significant progress over the last several years, many challenges and associated research opportunities remain in the development of high‐efficiency antennas for biointegrated electronic/optoelectronic systems.
Flexible and stretchable antennas are critical components of wireless, biointegrated electronics. An overview of material choices and design strategies is provided. Optimization methods and performance characteristics are considered for a range of applications, with an emphasis on wearable devices. The antennas can support data transmission, external control interfaces, power harvesting, and can also function as sensors of mechanical deformations.
•Skin-interfaced wearable sensors offer powerful capabilities for continuous sweat analysis.•Wearable sweat sensors enable precise assessments of health status and disease conditions outside of ...clinical settings.•Fundamental challenges in fluid handling, analytical performance, and energy storage restrict widespread deployment.•Continued platform maturation via commercialization increases utility for monitoring health, nutrition, and wellness status.
Sweat is a promising, yet relatively unexplored biofluid containing biochemical information that offers broad insights into the underlying dynamic metabolic activity of the human body. The rich composition of electrolytes, metabolites, hormones, proteins, nucleic acids, micronutrients, and exogenous agents found in sweat dynamically vary in response to the state of health, stress, and diet. Emerging classes of skin-interfaced wearable sensors offer powerful capabilities for the real-time, continuous analysis of sweat produced by the eccrine glands in a manner suitable for use in athletics, consumer wellness, military, and healthcare industries. This perspective examines the rapid and continuous progress of wearable sweat sensors through the most advanced embodiments that address the fundamental challenges currently restricting widespread deployment. It concludes with a discussion of efforts to expand the overall utility of wearable sweat sensors and opportunities for commercialization, in which advances in biochemical sensor technologies will be critically important.
PDF
