To date only few low-cost bio-based materials have been reported to be useful as TENGs. However, they still keep employing costly nanofabrication techniques. Herein, a new bio-based starch-cellulose TENG is fabricated without using complex equipment for the first time. Our results showed that, depending on the film thickness, electric outputs varied from 60 mV to 300 mV per 4 cm2 area. The thicker the film, the lower the electrical outputs, and vice versa. Moreover, FTIR-ATR analysis also showed that no chemical modification was made on the surface of starch after casting. Therefore, starch remained unmodified at the time of characterization, being this performance proper of a pristine starch. In addition, though organic starch isolation, fabrication of the proposed TENG was entirely handmade, thus avoiding use of complex equipment of nano- and micro-fabrication which resulted in the development of an eco-friendly TENG with very good performance according to the state-of-the-art.

Multi-functions devices attract much attention due to their great potential and large demands in wearable electronics. Besides some studies of integrated different functional devices as one, there is a novel strategy to fabricate multi-functions devices, that using one device to achieve two or more functions. Herein, we report the temperature sensing and energy storage multi-functions device based on graphene supercapacitor. By measuring the change of leakage current of supercapacitor, the obtained device could detect the environmental temperature. Integrating the planar-structure supercapacitor on one flexible printed circuit board with electronic components together, the obtain device presents perfect mechanical stability that no noticeable difference of both capacitance and leakage current under any bending status. Importantly, the temperature sensing function exhibits a high accuracy of 1 °C with a high resolution of 0.0588 °C. This work demonstrates the feasibility of the strategy of one device achieve two functions: using one supercapacitor to achieve temperature sensing and energy storage dual function simultaneously.

Stretchable electronics fabrication generally relies on fine-tuning adhesion forces, putting some restrictions on what the carrier layer can be. In contrast to adhesion, mechanical tangling makes more kinds of carrier materials available. Antibacterial, conductive, heat-responsive and other functions can be brought in by fiber networks as long as they are compatible with the highly selective silicon etch process. Mechanical grippers can also bring electronic contacts from one side of a mesh to the other, which is difficult to do on continuous thin films of other soft materials like silicone or polyimide. Our solution uses mechanical strain to produce large arrays of redundant grippers from planar thin-film designs.

Microsupercapacitors (MSCs) are miniaturized energy storage devices that can be integrated in an on-chip platform as a component of a power supply for Internet of things’ sensors. Integration of these on-chip MSCs require them to be fabricated through CMOS compatible fabrication techniques such as spin coating. One of the biggest challenges in spin coated MSCs is the poor surface adhesion. In this work, we present a CMOS compatible electrode deposition process with enhanced adhesion and retention for reduced graphene oxide (rGO) using spin coating. In order to improve the adhesion and surface uniformity of the deposited electrode material, the surface of Si/SiO2 wafers was subjected to roughening through Fe nanoparticle formation. A 4 nm thick Fe layer deposition substantially magnified the average mean surface roughness of the substrates. In comparison with substrates without the Fe deposition, the treated ones have more than 300% improvement in surface coverage and rGO mass retention after sonication testing. These results suggest that the surface roughening has a positive influence on electrode deposition via a spin-coating method.

We demonstrate that the extrusion speed of thermoplastic urethane elastomer can modify its optical transmission by a factor of more than 100. Varying extrusion speed at constant temperature may tune optical properties along the axis of a filament, for example creating absorbent regions that are sensitive to length and diameter changes, surrounded by more transmissive segments that carry the sensor signal over long distances. Such waveguiding in a stretchable optical fiber requires a stretchable cladding with lower refractive index than the core. In experiments toward a rugged, stretchable fiber cladding, we investigated whether solvents could modify the outer structure of the filaments. Soaking the filaments in NMP (n-methyl-2-pyrrolidone), then stretching the filaments while the solvent dried, turned out to modify the filaments in a way that solvents alone did not, creating porosity and reducing the appearance of optical clarity.

The current work focuses on optimizing aptamer scaffolds that are tailored to allow for the formation of binding pockets for both a redox active signaling molecule and the target miR-92a. These newly designed allosteric nucleic acid systems are studied for efficacy to undergo a target based conformational switch. Two hairpin scaffolds were designed with differing stem stabilities and were explored using fluorescence quenching measurements. The dose dependent data for the detection of miR-92a shows the importance of scaffold design where the stability of the intra-molecular hairpin structure has to be optimized for target binding. Additional experiments explored the selectivity of the aptamer scaffolds in the presence of competing miR’s and mismatched sequences. These results provide an important precursor to constructing nucleic acid scaffolds for the detection of miR’s using label-free redox signaling.

In this paper, we report on the flexible thin film piezoelectric nanogenerators based on two-dimensional ZnO nanoflakes (NFs) directly deposited onto flexible polyethylene terephthalate (PET) using a simple sonochemical reaction in aqueous solution at room temperature. Our sonochemical synthesis method is a rapid, highly stable, low-cost, and reproducible method, which can be performed at ambient conditions. These advantages of the sonochemical method allow the synthesis of many different ZnO nanostructures. The structural investigations using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD) indicated that the ZnO NFs grew with high level of crystallinity and without any thermal damage on the substrates. The fabrication of these device provides a promising solution for developing flexible and self-powered electronic devices particularly wearable and implantable sensors. This ZnO-NFs based nanogenerator provides 62 mV of potential and significant reproducibility having with lower p-value (0.0212).

Chainmail fabrics manufactured by selective laser sintering 3D printing have been magnetically functionalized to create a lightweight, 4D printed, actuating fabric. The post-processing method involves submerging the porous prints in commercial ferrofluid (oil-based magnetic liquid), followed by drying under heat. The actuation of the chainmail has been simulated using a rigid multi-body physics engine, and qualitatively matches experiment. Such magnetically actuating fabrics have potential to make thin, lightweight and comfortable wearable assistive devices.