‘Drawn-on-skin’ electronics offer breakthrough in wearable monitors

EurekAlert  July 30, 2020 The existing wearable bioelectronics are susceptible to motion artifacts as they lack proper adhesion and conformal interfacing with the skin during motion. A team of researchers in the US (University of Houston, University of Chicago) has developed ultra-conformal Drawn-on-Skin (DoS) electronics as a new bioelectronic platform for on-demand multifunctional, motion artifact-free sensing. The devices are based on the Ag flakes/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (Ag-PEDOT:PSS) composite, poly(3-hexylthiophene-2,5-diyl) nanofibrils (P3HT-NF), and ion gel as the conductive, semiconducting, and dielectric inks, respectively. As a versatile platform, DoS electronics devices such as thin-film transistors, strain sensors, and electrophysiological sensors have been developed. It […]

New organic material unlocks faster and more flexible electronic devices

Science Daily  July 15, 2020 Long-range and fast transport of coherent excitons is important for the development of high-speed excitonic circuits and quantum computing applications. By precisely stacking carbon and hydrogen molecules one over the other researchers in Australia have designed an organic semiconductor. The material is just one carbon atom thick which gives it the flexibility to be bent into any shape. The material is biodegradable or easily recyclable, thus avoiding the tonnes of e-waste generated by current generation electronic devices…read more. Open Access TECHNICAL ARTICLE 

Stretchable supercapacitors to power tomorrow’s wearable devices

Phys.org  March 19, 2020 A team of researchers in the US (Duke University, Michigan State University, MIT) has demonstrated a robust and high-performance stretchable electrode based on biaxially crumpled Au-coated carbon nanotube forest. It has nearly identical electrochemical performance at different measured charge/discharge rates under different strain conditions and a maximum specific capacitance of ∼6 mF cm−2 at the current density of 40 mA cm−2 under large strains, exhibiting superior mechanical and electrochemical stability. The researchers envision the supercapacitor being part of a power-independent, stretchable, flexible electronic system for applications such as wearable electronics or biomedical devices…read more. Open Access […]

Nano-thin flexible touchscreens could be printed like newspaper

Nanowerk  January 24, 2020 Researchers in Australia used a thin film common in cell phone touchscreens and shrunk it from 3D to 2D, using liquid metal chemistry. They synthesized flexible two-dimensional indium tin oxide (ITO) using a low-temperature liquid metal printing technique. The approach can directly deposit monolayer or bilayer ITO onto desired substrates, with the resulting bilayer samples offering a transparency above 99.3% and a sheet with low resistance. To illustrate the capabilities of the technique, they developed a capacitive touch screen using centimetre-sized monolayer ITO sheets…read more. TECHNICAL ARTICLE

Kirigami inspires new method for wearable sensors

Nanowerk  October 22, 2019 To make a material resistant to damage from the stress and strains of the human body’s natural movement researchers at the University of Illinois applied kirigami architectures to graphene to create sensors suitable for wearable devices. They put the active sensing element on an “island” between two “bridges” made from kirigami graphene. While the graphene did not lose any electrical signal despite the bending and tilting, it still took the load from the stretching and straining, enabling the active sensing element to remain connected to the surface. It made the graphene not only stretchable, strain-insensitive and […]

Researchers create washable sensor that can be woven into materials

Science Daily  May 16, 2019 Researchers in Canada have developed a low‐cost, tunable, and stretchable sensor fabric based on spandex yarns coated with graphene nanoplatelets through a dip‐coating process. It is wrapped into a stretchable silicone rubber sheath to protect the conductive layer against harsh conditions, which allows for fabricating washable wearable sensors. The covering sheath is tailored to achieve high stretchability beyond the sensing limit of 104%. Adjustable sensitivity is attained by manipulating spandex yarn immersion times. The testing indicates that further improvements in its accuracy could be achieved by fine-tuning the sensor’s material blend and improving its electrical […]

The future of stretchable electronics

Phys.org  March 26, 2019 In this review article researchers in China highlight the advances in stretchable electronics, with an emphasis on underlying methods and engineering strategies in stretchable device construction and their applications. Currently there are two main strategies for manufacturing stretchable electronics. The first is to use intrinsically stretchable materials, such as rubber, which can endure large deformations but have high electrical resistance. The second method is to make non-flexible materials stretchable using innovative design. In the future, stretchable electronics may be enhanced with new capabilities, such as wireless communication, self-charging or even self-healing. Bringing stretchable electronic devices to […]

Berkeley engineers develop origami electronics from cheap, foldable paper

UC Berkeley  July 6, 2018 An international team of researchers (USA – UC Berkeley, Redstone Arsenal, China) has developed a direct‐write laser‐patterning technology to engrave random shapes of metal‐carbide–graphene composites (MCG) on different types of paper (A4, wiper, filter paper, etc.). These commercial papers are soaked with solutions containing metal ions in gelatin media, which is the major component of the “jelly”. The MCG–paper substrates are applied in a 3D foldable energy generator, electrochemical sensors, and supercapacitors. They see many potential applications for the new, disposable paper electronics, circuitry to detect heavy metal contamination could be “written” on paper to […]