Deformable electronic devices that are impervious to mechanical influence when mounted on surfaces of dynamically changing soft matters have great potential for next‐generation implantable ...bioelectronic devices. Here, deformable field‐effect transistors (FETs) composed of single organic nanowires (NWs) as the semiconductor are presented. The NWs are composed of fused thiophene diketopyrrolopyrrole based polymer semiconductor and high‐molecular‐weight polyethylene oxide as both the molecular binder and deformability enhancer. The obtained transistors show high field‐effect mobility >8 cm2 V−1 s−1 with poly(vinylidenefluoride‐co‐trifluoroethylene) polymer dielectric and can easily be deformed by applied strains (both 100% tensile and compressive strains). The electrical reliability and mechanical durability of the NWs can be significantly enhanced by forming serpentine‐like structures of the NWs. Remarkably, the fully deformable NW FETs withstand 3D volume changes (>1700% and reverting back to original state) of a rubber balloon with constant current output, on the surface of which it is attached. The deformable transistors can robustly operate without noticeable degradation on a mechanically dynamic soft matter surface, e.g., a pulsating balloon (pulse rate: 40 min−1 (0.67 Hz) and 40% volume expansion) that mimics a beating heart, which underscores its potential for future biomedical applications.
Deformable organic nanowire (NW) field‐effect transistors (FETs) with mechanical reliability are demonstrated with highly ductile and deformable NWs as the semiconductor. The NWs maintain a continuous structure under 100% strain in both channel length and width directions of the transistors. Stretchable FETs with single NWs are operated stably on a 3D soft matter substrate with dynamic volume expansion and contraction that mimics a beating heart.
Emulating essential synaptic working principles using a single electronic device has been an important research field in recent years. However, achieving sensitivity and energy consumption comparable ...to biological synapses in these electronic devices is still a difficult challenge. Here, we report the fabrication of conjugated polyelectrolyte (CPE)-based artificial synapse, which emulates important synaptic functions such as paired-pulse facilitation (PPF), spike-timing dependent plasticity (STDP) and spiking rate dependent plasticity (SRDP). The device exhibits superior sensitivity to external stimuli andlow-energy consumption. Ultrahigh sensitivity and low-energy consumption are key requirements for building up brain-inspired artificial systems and efficient electronic-biological interface. The excellent synaptic performance originated from (i) a hybrid working mechanism that ensured the realization of both short-term and long-term plasticity in the same device, and (ii) the mobile-ion rich CPE thin film that mediate migration of abundant ions analogous to a synaptic cleft. Development of this type of artificial synapse is both scientifically and technologically important for construction of ultrasensitive highly-energy efficient and soft neuromorphic electronics.
An artificial synapse is fabricated to emulate biological functions with high sensitivity and low-energy consumption Display omitted
•Conjugated polyelectrolyte (CPE)-based artificial synapse was fabricated.•Important working principles of a biological synapse are emulated.•The artificial synapse potentially exhibited ultrahigh sensitivity and low energy consumption.
Dual‐gate field‐effect transistors (FETs) based on organic semiconductor polymer and SiOx as the topmost active sensing layer permit monitoring of pH in physiologically relevant conditions in a fast ...and reversible fashion. Beyond that, due to the bottom gate‐induced field effect, such sensors exhibit tunable sensitivity and provide faster continuous measurements compared to conventional bulky glass bulb pH sensors. pH response of bare SiOx is evaluated independently by means of voltmeter measurements. When assembled in dual‐gate architecture, the pH response of FET devices scales in agreement with the theoretical model, which assumes capacitive coupling, exhibiting an amplification of up to 10. This opens up the possibility for reversible and reliable sensing based on organic semiconductors well beyond pH sensors.
Dual‐gate field‐effect transistors with organic semiconducting polymer and silicon monoxide as topmost active sensing layer allow monitoring of pH in physiological relevant conditions. pH response of SiOx is evaluated independently by means of voltmeter measurements. Once assembled in dual‐gate architecture, pH response scales according to capacitive coupling, leading to an amplification of up to 10.
Semiconducting single‐walled carbon nanotubes (swCNTs) are a promising class of materials for emerging applications. In particular, they are demonstrated to possess excellent biosensing capabilities, ...and are poised to address existing challenges in sensor reliability, sensitivity, and selectivity. This work focuses on swCNT field‐effect transistors (FETs) employing rubbery double‐layer capacitive dielectric poly(vinylidene fluoride‐co‐hexafluoropropylene). These devices exhibit small device‐to‐device variation as well as high current output at low voltages (<0.5 V), making them compatible with most physiological liquids. Using this platform, the swCNT devices are directly exposed to aqueous solutions containing different solutes to characterize their effects on FET current–voltage (FET I–V) characteristics. Clear deviation from ideal characteristics is observed when swCNTs are directly contacted by water. Such changes are attributed to strong interactions between water molecules and sp2‐hybridized carbon structures. Selective response to Hg2+ is discussed along with reversible pH effect using two distinct device geometries. Additionally, the influence of aqueous ammonium/ammonia in direct contact with the swCNTs is investigated. Understanding the FET I–V characteristics of low‐voltage swCNT FETs may provide insights for future development of stable, reliable, and selective biosensor systems.
Low voltage carbon nanotube field‐effect transistors employing a rubbery double‐layer dielectric allow exposing devices to aqueous solutions and study effects on current–voltage characteristics. Selective response to Hg2+ is discussed along with reversible pH effect and compared with ammonium/ammonia in direct contact with the carbon nanotube network. Unraveling the sensing mechanisms is important and may provide insight for the development of stable, reliable and selective biosensor systems.
Microgravity has proved to be an ideal condition to grow crystals. In article number 2101777, Raphael Pfattner, Tiago Sotto Mayor, Daniel Ruiz‐Molina, Josep Puigmartí‐Luis, and co‐workers demonstrate ...how to generate simulated microgravity on Earth to grow 2D porous crystalline molecular frameworks such as 2D metal–organic frameworks and 2D covalent organic frameworks.
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