Nanowerk December 23, 2024 3D buckling makes stretchability possible in devices but, when applied to piezoelectric devices due to the uneven distribution of internal strain during deformation. When strains with opposite directions simultaneously affect piezoelectric materials, the electric output can decrease due to cancellation. Researchers in the Republic of Korea developed an electrode design tailored to the direction of strain and a circuit configuration that prevented electric output cancellation. These designs provided stretchability to piezoelectric nanogenerators (PENGs) and minimized electric output loss. Using an inorganic piezoelectric material with a high piezoelectric coefficient, they demonstrated the dynamics of energy harvesting. In […]
Tag Archives: Wearable electronics
Wearable textile captures energy from body movement to power devices
Phys.org June 5, 2023 Some of the energy supply units cannot meet the energy requirements for wearable electronics which requires its energy supply part to be flexible, wearable, integratable and sustainable. Researchers at the Georgia Institute of Technology have developed wearable sustainable energy harvesting-storage hybrid self-charging power textile. The power textile consists of a coaxial fiber-shaped polylactic acid/reduced graphene oxide/polypyrrole (PLA-rGO-PPy), triboelectric nanogenerator (fiber-TENG) which is flexible can harvest low-frequency and irregular energy during human motion, and a novel coaxial fiber-shaped supercapacitor (fiber-SC) as an energy storage unit. The integrated power textile can provide an efficient route for sustainable working […]
Human-machine interfaces work underwater, generate their own power
Nanowerk August 9, 2022 Skin-integrated electronics that directly interact with machines are transforming our ways of life toward the emerging trend of the metaverse. Researcher at UCLA have developed a stretchable, inexpensive, and waterproof magnetoelastic sensor array as a secondary skin for self-powered human–machine interaction. The sensor array has the giant magnetomechanical coupling layer made up of nanomagnets and a porous silicone rubber matrix, and the magnetic induction layer, which are coils patterned by liquid metal. With programmable functionalities the sensor array can supply different commands by producing bespoke electric signals from human finger touch with an optimal signal-to-noise ratio […]
Engineers invent ultra-fast manufacturing technology
Nanowerk November 3, 2021 Current printing techniques for printing soft electronics (PSE) are still facing long-lasting challenges in addressing the conflict between printing speed and performance. A team of researchers in the US (California Polytechnic State University, UC San Diego, University of South Florida, Carnegie Mellon University) has developed a new corona-enabled electrostatic printing (CEP) technique for ultra-fast roll-to-roll (R2R) manufacturing of binder-free multifunctional e-skins. CEP-printed graphene e-skins were demonstrated to possess an outstanding strain sensing performance. The binder-free feature of the CEP-assembled networks enables them to provide pressure sensitivity as low as 2.5 Pa and capability to detect acoustic […]
‘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 […]
Untwisting plastics for charging internet-of-things devices
Science Daily April 16, 2020 To use body heat to charge some types of micro-devices and sensors lightweight, non-toxic, wearable, and flexible thermoelectric generators are required. Japan studied the thermoelectric properties of highly conductive thiophene-based polymer, called PBTTT. They doped the polymer with a thin ion electrolyte gel, which is known to improve conductivity that infiltrates the polymer successfully when a specific electric voltage is applied. They found that, without the electrolyte gel, the PBTTT chain is highly twisted. Doping it with a critical amount of electrolyte untwists the chain and creates links between its crystalline parts, improving electron conductivity. […]
Integrating microchips for electronic skin
Science Daily January 22, 2020 To closely replicate natural skin, it is necessary to interconnect a large number of individual sensors. An international team of researchers (Japan, Germany) developed a sensor system that consists of a 2 x 4 array of magnetic sensors, an organic bootstrap shift register, required for controlling the sensor matrix, and organic signal amplifiers. All electronic components are based on organic thin-film transistors and are integrated within a single platform. The researchers demonstrated that the system has a high magnetic sensitivity and can acquire the two-dimensional magnetic field distribution in real time and very robust against […]
Wearable air conditioning without needing electricity
Nanowerk January 6, 2019 By using multiscale porous Styrene-ethylene-butylene-styrene (SEBS) as supporting substrates a team of researchers in the US (University of Missouri, Argonne National Laboratory) has developed multifunctional on-skin electronics with outstanding passive-cooling capabilities, delivering around 6 °C cooling effects under a solar intensity of 840 W⋅m−2. Other desired properties, rooted in porous SEBS substrates, include high breathability and outstanding waterproofing. In addition, a variety of bioelectronic devices are made on porous SEBS substrates via spray printing of silver nanowires. The enabled devices demonstrate high performance and are recyclable. Currently, the device is a small wired patch, and researchers […]
Making tiny antennas for wearable electronics
Science Daily November 20, 2019 Researchers in South Korea made the antenna by spray-coating several layers of NbSe2 nanosheets onto a plastic substrate. In tests an 885 nm-thick antenna, a 10 × 10 mm patch of the ultrathin material performed well, with a radiation efficiency of 70.6% propagating radio frequency waves in all directions. By changing the length of the antenna, the frequency could be tuned from 2.01 to 2.80 GHz, which includes the frequency required by Bluetooth and Wi-Fi technologies. The antenna could be bent and stretched without large changes in its performance. In addition to wearable electronics, the […]
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 […]