Arrays of angled microfibers with a gecko-inspired structure were fabricated from stiff thermoplastic polymer (polypropylene) elastic properties similar to those β-keratin natural setae. Friction experiments demonstrated that this fibrillar surface exhibits directional adhesion. Sliding clean glass surfaces against and along the microfiber direction without applying an external normal force produced apparent shear stress 0.1 4.5 N/cm2, respectively. This adhesion is interpreted in context...

A subdermally implantable flexible photovoltatic (IPV) device is proposed for supplying sustainable electric power to in vivo medical implants. Electric properties of the implanted IPV are characterized live animal models. Feasibility this strategy demonstrated by operating a pacemaker with subdermal which generates DC ≈647 μW under skin. As service our authors and readers, journal provides supporting information supplied authors. Such materials peer reviewed may be re-organized online...

Notched islands on a thin elastomeric substrate serve as platform for dual-junction GaInP/GaAs solar cells with microscale dimensions and ultrathin forms stretchable photovoltaic modules. These designs allow high degree of stretchability areal coverage, they provide natural form strain-limiting behavior, helping to avoid destructive effects extreme deformations. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not...

As Latino populations in the United States increase, accurately characterizing their turnout is central to understanding how post-New Deal party system will evolve. Yet we presently have little data on either or dynamic by which such participation occurs. We estimate voting rates 1996 presidential election validating selfreported from a post-election survey of Latinos California, Florida, and Texas. then use these estimates as dependent variables for multivariate models turnout. The show...

Natural gecko toes covered by nanomicro structures can repeatedly adhere to surfaces without collecting dirt. Inspired geckos, we fabricated a high-aspect-ratio fibrillar adhesive from stiff polymer and demonstrated self-cleaning of the during contact with surface. In contrast conventional pressure-sensitive (PSA), contaminated synthetic recovered about 33% shear adhesion clean samples after multiple contacts clean, dry

Gecko-inspired microfibre arrays with 42 million polypropylene fibres cm −2 (each fibre elastic modulus 1 GPa, length 20 μm and diameter 0.6 μm) were fabricated tested under pure shear loading conditions, after removing a preload of less than 0.1 N . After sliding to engage fibres, 2 patches developed up 4 force an estimated contact region 0.44 The control unfibrillated surface had no measurable force. For comparison, natural setal patch the same conditions on smooth glass showed...

The adhesive pads of geckos provide control normal force by controlling the applied shear force. This frictional adhesion effect is one key principles used for rapid detachment in animals running up vertical surfaces. We developed polypropylene microfibre arrays composed vertical, 0.3 μm radius fibres with elastic modulus 1 GPa which show this first time using a stiff polymer. In absence forces, these minimal adhesion. However, sliding parallel to substrate spherical probe produces not seen...

Physiological signals provide important information for biomedical applications and, more recently, in the form of wearable electronics active interactions between bodies and external environments. Multiple physiological sensors are often required to map distinct from multiple points over large areas diverse applications. In this paper, we present a reusable, multichannel, surface electromyography (EMG) sensor array that covers muscles relatively areas, with compliant designs different...

Significance One of the highest demands in biomedical electronic implants is to provide a sustainable electrical power for extended healthy life without battery replacement surgeries. The reported technology enables providing wirelessly through live tissues as demonstrated by key function, i.e., stimulation, implantable medical electronics at level full system. approach capable enough (74.1 μW/cm 2 , active photovoltaic area: 11.1 mm ) indoor or outdoor during day and night should lead...

The recent commercial success of flexible and foldable displays has resulted in growing interest stretchable electronics which are considered to be the next generation optoelectronic technology. Stretchable display technologies being intensively studied for versatile applications including wearable, attachable, shape changeable electronics. In this paper, we present high fill factor, inorganic light-emitting diode (LED) fabricated by connecting mini-LEDs interconnects a double-layer modular...

Abstract Stretchable electronics are of huge interest as they can be useful in various irregular non-planar or deformable surfaces including human bodies. High density multi-functional stretchable beneficial reliably used more compact regions. However, simply stacking multiple layers may increase induced strain, reducing degree stretchability. Here, we present the design approach for multilayer that provide a similar stretchability compare to single layer although much form. We experimental...

We report the fabrication from a hard polymer of lamellar structures that act as base support planes for high-aspect ratio nanofiber arrays. experimentally show arrays on lamellae can adhere to both planar and nonplanar surfaces, exhibiting 5 times greater shear strength 100 mum peak-to-peak grating than without structure. The observed behavior surfaces is attributed high compliance flaps. combined measured be about 160 higher flat nonlamellar backing layer.

Recent research for unconventional types of electronics has revealed that it is necessary to transfer-print high-performance microelectronic devices onto diverse surfaces, including flexible or stretchable relieve mechanical constraints associated with conventional rigid electronics. Picking up and placing ultrathin microdevices without damage are critical procedures the successful manufacture various This paper introduces elastomeric angled microflaps have reversible adhesion; i.e., they...

High-performance electronic devices integrated onto unconventional substrates provide opportunities for use in diverse applications, such as wearable or implantable forms of devices. However, the interlayer adhesives between and often limit processing temperature cause electrical thermal resistance at interface. This paper introduces a very simple but effective transfer printing method that does not require an adhesive. Controlling bending radius flat stamp enables picking up microscale...

Conventional connectors utilize mechanical, magnetic, or electrostatic interactions to enable highly specific and reversible binding of the components (i.e., mates) for a wide range applications. As are miniaturized small scales, number shortcomings, including low strength, high engagement/disengagement energies, difficulties with engagement, fabrication challenges, lack reliability presented that limit their successful operation. Here, we report unisex, chemical based on hybrid,...

Strategies are presented to achieve ultrathin light-emitting diodes using the technique of epitaxial liftoff in ways that protect materials from etchants used for release and tether devices underlying wafer subsequent transfer printing onto substrates interest. The results lead an advanced interconnection scheme vertical device layout facilitate electrical contacts system integration on flexible substrates.

Monitoring cardiovascular signals such as heart rate and blood flow provides critically important healthcare information about patients under medical care. However, when the sensors are worn for extended times, sometimes require higher mechanical compatibility with soft deformable tissues. In this paper, we report an attachable flexible pulse sensor (bending radius: 2.4 mm), integrated micro-inorganic photodetectors (thickness: 4.1 μm, photocurrent: 8.99 μA 1.5 mW/cm2) a red light emitting...

Developing electronics in unconventional forms provides opportunities to expand the use of diverse applications including bio-integrated or implanted electronics. One key challenges lies integrating semiconductor microdevices onto substrates without glue, high pressure temperature that may cause damage microdevices, interfaces. This paper describes a solution based on natural gecko setal arrays switch adhesion mechanically and off, enabling pick place manipulation thin microscale materials...

Wearable flexible electronics often require sustainable power sources that are also mechanically to survive the extreme bending accompanies their general use. In general, thinner microelectronic devices under less strain when bent. This paper describes strategies realize ultra-thin GaAs photovoltaics through interlayer adhesiveless transfer-printing of vertical-type onto metal surfaces. The photovoltaic recycle reflected photons by means bottom electrodes. Systematic studies with four...

In order to be deployed in real-world driving environments, self-driving cars must able recognize and respond exceptional road conditions, such as highway workzones, because unusual events can alter previously known traffic rules geometry. this paper, we present a set of computer vision methods that recognize, through identification workzone signs, the bounds temporary changes environments. Through testing using video data about workzones recorded under various weather our approach was...