High-performance top-gated carbon nanotube field-effect transistors (CNT FETs) with a gate length of 5 nanometers can be fabricated that perform better than silicon complementary metal-oxide semiconductor (CMOS) FETs at the same scale. A scaling trend study revealed that the scaled CNT-based devices, which use graphene contacts, can operate much faster and at much lower supply voltage (0.4 versus 0.7 volts) and with much smaller subthreshold slope (typically 73 millivolts per decade). The 5-nanometer CNT FETs approached the quantum limit of FETs by using only one electron per switching operation. In addition, the contact length of the CNT CMOS devices was also scaled down to 25 nanometers, and a CMOS inverter with a total pitch size of 240 nanometers was also demonstrated.

Intrinsically stretchable bioelectronic devices based on soft and conducting organic materials have been regarded as the ideal interface for seamless and biocompatible integration with the human body. A remaining challenge is to combine high mechanical robustness with good electrical conduction, especially when patterned at small feature sizes. We develop a molecular engineering strategy based on a topological supramolecular network, which allows for the decoupling of competing effects from multiple molecular building blocks to meet complex requirements. We obtained simultaneously high conductivity and crack-onset strain in a physiological environment, with direct photopatternability down to the cellular scale. We further collected stable electromyography signals on soft and malleable octopus and performed localized neuromodulation down to single-nucleus precision for controlling organ-specific activities through the delicate brainstem.

Polymeric electronic materials have enabled soft and stretchable electronics. However, the lack of a universal micro/nanofabrication method for skin-like and elastic circuits results in low device density and limited parallel signal recording and processing ability relative to silicon-based devices. We present a monolithic optical microlithographic process that directly micropatterns a set of elastic electronic materials by sequential ultraviolet light–triggered solubility modulation. We fabricated transistors with channel lengths of 2 micrometers at a density of 42,000 transistors per square centimeter. We fabricated elastic circuits including an XOR gate and a half adder, both of which are essential components for an arithmetic logic unit. Our process offers a route to realize wafer-level fabrication of complex, high-density, and multilayered elastic circuits with performance rivaling that of their rigid counterparts.

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Carbon nanotube (CNT)-based electronics are a potential candidate to replace silicon complementary metal-oxide-semiconductor (CMOS) technology, which will soon meet its performance limit at the 7 or 5 nm technology node 1,2 . Prototype device studies using individual CNTs have shown that nanotube electronics have the potential to outperform Si CMOS technology in both performance and power consumption [3][4][5][6] , and are even close to the theoretical limits for all field-effect-transistor(FET)-based binary switches 7,8 . Recently, FETs were fabricated using aligned CNT arrays, and shown to have a higher channel conductance (at a lower bias) than that of Si CMOS FETs 9 . However, the key performance metrics reported for such CNT FETs, including on-state current density (I on ) and transconductance (g m ), are still substantially lower than those of conventional Si CMOS FETs at the same characteristic length [9][10][11][12][13] . The ideal material system for high-performance CNT electronics has been identified as a parallel array film of intrinsic pure semiconductor single-walled nanotubes of a single chirality with a diameter of approximately 1.3 nm and no defects, and a tube-tube spacing of 5-8 nm (ref. 14 ). Although such an ideal material system is yet to be realized, many breakthroughs in the purification and controlled synthesis of CNTs have been made in recent years [15][16][17][18][19] , suggesting the possibility of achieving the required nanotube purity and array density before 2020 14 . Using randomly oriented or aligned CNT array films, various types of CNT thin-film FETs have been fabricated [9][10][11][12][13] . However, hindered by the limited performance of nanotube FETs, the operation speed of CNT integrated circuits (ICs) 20-31 typically falls short of their expected terahertz potential, and that achieved by Si CMOS circuits (gigahertz), by several orders of magnitude. Notably, CNT-based ring oscillators (ROs) with an oscillation frequency (f o ) of 282 MHz have recently been reported 32 . However, CNT-thin-film-based ICs typically have a working frequency of less than 1 MHz, which might be useful for flexible electronics, but is not suitable for mainstream high-performance CMOS technology 33 . In this study, we used a randomly oriented CNT film to build CNT FETs and ICs, fabricating, in particular, five-stage ROs with f o of up to 5.54 GHz. The random CNT film is essentially the same as a network film, but here we used the term 'random film' to emphasize that our FETs are contact dominated and have a different transport mechanism to that of junction-dominated network-type FETs 34,35 . In principle, aligned CNT arrays would provide better device performance, but it remains a challenge to obtain wafer-scale aligned CNT arrays with high uniformity, high density and high semiconductor purity for constructing high-performance ICs. Although it is not the ideal scheme, the FET-and IC-based random CNT film can nevertheless provide a feasible demonstration to assess the floor-level performance (f...

Field-effect transistor (FET) biosensors based on low-dimensional materials present the advantages of low cost, high speed, small size, and excellent compatibility with integrated circuits (ICs). In this work, we fabricated highly sensitive FET-based DNA biosensors based on chemical vapor deposition (CVD)-grown monolayer MoS2 films in batches and explored their application in noninvasive prenatal testing (NIPT) for trisomy 21 syndrome. Specifically, MoS2 was functionalized with gold nanoparticles (Au NPs) of an optimized size and at an ideal density, and then, probe DNAs for the specific capture of target DNAs were immobilized on the nanoparticles. The fabricated FET biosensors are able to reliably detect target DNA fragments (chromosome 21 or 13) with a detection limit below 100 aM, a high response up to 240%, and a high specificity, which satisfy the requirement for the screening of Down syndrome. In addition, a real-time test was conducted to show that the biosensor clearly responds to the target DNA at concentrations as low as 1 fM. Our approach shows the potential for detecting the over-expression of chromosome 21 in the peripheral blood of pregnant women and achieving Down syndrome screening.

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