RESUMO
Edible electronics is an emerging research field targeting electronic devices that can be safely ingested and directly digested or metabolized by the human body. As such, it paves the way to a whole new family of applications, ranging from ingestible medical devices and biosensors to smart labelling for food quality monitoring and anti-counterfeiting. Being a newborn research field, many challenges need to be addressed to realize fully edible electronic components. In particular, an extended library of edible electronic materials is required, with suitable electronic properties depending on the target device and compatible with large-area printing processes, to allow scalable and cost-effective manufacturing. In this work, we propose a platform for future low-voltage edible transistors and circuits that comprises an edible chitosan gating medium and inkjet-printed inert gold electrodes, compatible with low thermal budget edible substrates, such as ethylcellulose. We report the compatibility of the platform, characterized by critical channel features as low as 10 µm, with different inkjet-printed carbon-based semiconductors, including biocompatible polymers present in the picogram range per device. A complementary organic inverter is also demonstrated with the same platform as a proof-of-principle logic gate. The presented results offer a promising approach to future low-voltage edible active circuitry, as well as a testbed for non-toxic printable semiconductors.
Assuntos
Quitosana , Recém-Nascido , Humanos , Semicondutores , Celulose , EletrônicaRESUMO
Recent advancements in the field of electronics have paved the way to the development of new applications, such as tattoo electronics, where the employment of ultraconformable devices is required, typically achievable with a significant reduction in their total thickness. Organic materials can be considered enablers, owing to the possibility of depositing films with thicknesses at the nanometric scale, even from solution. However, available processes do not allow obtaining devices with thicknesses below hundreds of nanometres, thus setting a limit. Here, we show an all-organic field effect transistor that is less than 150 nm thick and that is fabricated through a fully solution-based approach. Such unprecedented thickness permits the device to conformally adhere onto nonplanar surfaces, such as human skin, and to be bent to a radius lower than 1 µm, thereby overcoming another limitation for field-effect transistors and representing a fundamental advancement in the field of ultrathin and tattoo electronics.
RESUMO
Hybrid quantum wells are electronic structures where charge carriers are confined along stacked inorganic planes, separated by insulating organic moieties. 2D quantum-confined hybrid materials are of great interest from a solid-state physics standpoint because of the rich many-body phenomena they host, their tunability and easy synthesis, allowing the creation of material libraries. In addition, from a technological point of view, 2D hybrids are promising candidates for efficient, tunable, low-cost materials impacting a broad range of optoelectronic devices. Different approaches and materials have, therefore, been investigated, with the notable example of 2D metal halide hybrid perovskites. Despite the remarkable properties of such materials, the presence of toxic elements like lead is not desirable in applications and their ionic lattices may represent a limiting factor for stability under operating conditions. Therefore, non-ionic 2D materials made with non-toxic elements are preferable. In order to expand the library of possible hybrid quantum well materials, herein, we consider an alternative platform based on non-toxic, self-assembled, metal-organic chalcogenides. While the optical properties have been recently explored and some unique excitonic characters highlighted, photo-generation of carriers and their transport in these lamellar inorganic/organic nanostructures and critical optoelectronic aspects remain totally unexplored. We hereby report the first investigation on the electrical properties of the air-stable [AgSePh]∞ 2D coordination polymer in the form of nanocrystal (NC) films readily synthesized in situ and at low temperature, compatible with flexible plastic substrates. The wavelength-dependent photo-response of the NC films suggests the possible use of this material as a near-UV photodetector. We therefore built a lateral photo-detector, achieving a sensitivity of 0.8 A W-1 at 370 nm, thanks to a photoconduction mechanism, and a cut-off frequency of â¼400 Hz, and validated its reliability as an air-stable UV detector on flexible substrates.
