Seamless integration/Chronic stability (white arrows indicate mesh ribbons)
Syringe-injection of mesh electronics
Cyborg cardiac tissue
Kinked nanowire nanoFET sensor
Shape-selective nanowire assembly
Plateau-Rayleigh crystal growth
An ultra-flexible macroporous mesh electronic network seamlessly integrates and interpenetrates with neural networks in vivo
Syringe-injectable mesh electronics with tissue like mechanical properties and open macroporous structures
Syringe-injectable nanoelectronics seamlessly integrate with and record activity within the brain
Periodic shell nanowires grown by Plateau-Rayleigh crystal growth
A diagram showing a core/shell silicon nanowire device converting light into electric current through the creation of electron (e)-hole (h)pairs.
Researchers at Harvard University and the MITRE Corporation have built an ultra-tiny computer from an assembly of nanowires that is the densest, most complex nanoelectronic system ever fabricated from the bottom up.
A sample of nanoelectronic circuitry from our cyborg brain tissue project on display in the London Science Museum’s “Who Am I?” exhibition, which explores human identity and how it is affected by new discoveries in biomedical science; photo by the Science Museum, London
Cyborg Neural Tissue: Seamless integration of 3D nanoelectronic and neural networks
3D Macroporous Nanoelectronic Circuits
Nanoelectronic Blood Vessel
BIT-FET Device Probing Interior of Living Cell
Novel Branched Intracellular Nanotube Field-Effect Transistor (BIT-FET) Device
Influence of Cross-sectional Morphology on Light Absorption: Simulated EQE spectra for a hexagonal (solid red) and rectangular (solid blue) NW with the same diameter of 260 nm.
Size-dependent EQE (External Quantum Efficiency) Spectra of Si NWs. (A) Experimental (solid black) and simulated (dashed red) EQE spectra for NWs with diameters of 170 (top), 280 (middle), and 380 nm (bottom). Insets: absorption mode profiles calculated by 3-D FDTD simulations. (B) Size-dependent photocurrent values calculated from EQE spectra and 1-sun reference spectrum.
(1) U-shaped KNWs with a nanoFET at the tip of the “U,” (2) V-shaped KNWs with series multi-nanoFETs along the arm and at the tip of the “V,” and (3) W-shaped multiplexed KNWs integrating nanoFETs at the two tips of “W.”
Schematic of coaxial NW building blocks (blue indicates p-type doped core and beige indicates n-type doped shells); Schematic of typical silicon core/shell NW device fabricated from one NW building block on arbitrary substrate with integrated back-side reflector; Schematic illustrating potential for new device architecture using distinct NW building blocks within each layer. Colors indicate peak wavelength of light absorbed for particular NW morphology.
FDTD simulations of resonant mode spatial profiles for p/in (profiles 1-3) and p/pin (profiles 4-6) structures. All profiles are for TM polarizations and use a linear color scale representing absorption (not electric field intensity) within the mesoscopic structures. Resonant modes labeled 3 and 6 correspond to whispering-gallery type modes while all others correspond to Fabry-Perot resonances.
Integrating nanoelectronics with cells and tissue.
Nanosensors for the Detection of Biological and Chemical Species. Play the movie to see how nanowire field effect transistors (NW-FETs) can be configured as ultrasensitive and selective sensors of chemical and biological species.
Building a Nanocomputer. Click on the play icon to see how a universal architecture for nanoscale computing can be assembled from nanowire building blocks via the bottom-up paradigm.
Virus Binding to a Sensor. Nanowire devices represent nearly ideal sensor elements since they occupy a size regime similar to biological macromolecules. Click on the play icon to see a movie of a single virus binding to a nanosensor array.
(A) Measurement schematics. (top) Overview of a NWFET array fabricated on a transparent substrate, with an acute rat olfactory slice oriented with pyramidal cell layer over the devices. (bottom left) Zoom-in of device region illustrating interconnected neurons and NWFETs. (bottom right) Photograph of the assembled sample chamber.
(B) Conductance recording from a NWFET (lower traces) in the same region as neuron used to record cell-attached patch clamp results (upper traces). Stimulation in the LOT was performed with strong (200 A, red traces) and weak (50 A, blue traces) 200 s current pulses. The open triangle marks the stimulation pulse. When the stimulation intensity is weak, the signals representing the action potentials disappear in both cases.
(C) 2D mapping of heterogeneous activities in the pyramidal cell layer. This is an optical image of an acute slice over a 4×4 NWFET array. Signals were recorded simultaneously from the 8 devices indicated on the image. Crosses along the LOT fiber region of the slice mark the stimulation spots a through h. Scale bar represents 100 m.
(D) Maps of the relative signal intensity or activity for devices 1-8 in color scale for different stimulation positions, demonstrating clearly how heterogeneous activity can be resolved with much higher resolution than by conventional techniques. This facilitates study of the dynamic functional connectivity in complex neuron circuits.
See Proc. Natl. Acad. Sci. 107, 1882-1887 (2010)
Cohen-Karni et al. reported for the first time studies of graphene field effect transistors (Gra-FETs) as well as combined Gra- and NW-FETs interfaced to electrogenic cells. In this study 1-D Si NW-FETs incorporated side by side with the 2-D Gra-FET devices highlighted limits in both temporal resolution and multiplexed measurements from the same call for the different types of devices. Nano Lett. 10, 1098-1102 (2010)
Long coherent spin qubit in a Ge/Si heterostructure nanowire. Scanning electron micrograph of a spin qubit device. The nanowire runs horizontally underneath a gate oxide. Inset, High resolution TEM image shows a typical core/shell nanowire.ï»¿
Two integrated programmable nanowire logic circuit tiles on a glass substrate. These building blocks can be constructed via bottom-up assembly on diverse substrates such as transparent or flexible plastics.
A high-performance single nanowire device illuminated under 1-sun simulated solar conditions yields a current density exceeding 10 mA/cm^2, an open circuit voltage of 0.42 V, and a high fill factor. Shown in the inset is an SEM image of the core-shell nanowire device with selectively patterned metal contacts.
False-color SEM image of Shewanella MR-1 cells on electrodes with nanoholes (scale bar 1 micron). Proc. Natl. Acad. Sci. USA 107, 16806-16810 (2010).
Kinked silicon nanowire can be synthesized in various configurations through a nanotectonic approach. Such a structure might be used as novel confined electrical interface with cells and tissue.
Schematic of a kinked-nanowire nanoFET sensor probing the interior of a cell.
Nanowires with a core-shell geometry can be tailored to have diverse electrical and optical properties. Shown here is a false-color SEM image of a modulation doped core-shell nanowire which has been designed to function as a stand-alone nanoscale solar cell.
Scanning electron microscopy (SEM) image of a programmable nanowire logic circuit tile assembled bottom-up for computational functionalities such as full-adder. The tile can be scaled up into a fully-functional integrated nanoprocessor.”
First electrical recordings of intracellular potential with three-dimensional Si nanowire field effect transistor probe. Nature Nanotechnol. 4, 824-829 (2009) Image from Research Highlight in Nature 446, 904 (2010).
A ‘nanotectonic’ approach has been developed that provides iterative control over the nucleation and growth of nanowires. Dopant-modulated structures with specific device functions can be precisely localized at the kinked junctions of these new nanomaterials.
Vertically interconnected, three-stage CMOS ring oscillators were fabricated using layer-1 InAs nanowire n-FETs and layer-2 Ge/Si nanowire p-FETs. The circuit measurements demonstrated stable, self-sustained oscillations with a maximum frequency of 108 MHz, which represents the highest-frequency integrated circuit based on chemically synthesized nanoscale materials. Proc. Natl. Acad. Sci. USA 106, 21035-21038 (2009).
An artist’s rendition of Lieber group research, depicting an AFM probe comprised of a carbon nanotube modified with a biotin molecule, is on the cover of the Second Edition of the textbook Chemistry: A Molecular Approach (Prentice Hall, 2010), by Nivaldo Tro. For the original publication describing this research, see S.S. Wong, E. Joselevich, A.T. Woolley, C.L. Cheung and C.M. Lieber, “Covalently functionalized nanotubes as nanometer probes for chemistry and biology,” Nature 394, 52-55 (1998).
Using a ‘nanotectonic’ approach that provides iterative control over nanowire nucleation and growth, kinked nanowires can be grown in which straight sections of controllable length are separated by triangular joints. This is a composite of a false-color scanning electron microscope image of a single multiply-kinked nanowire with a diameter of 80 nm and a segment length of 1 micron. Nature Nanotechnol. 4, 824-829 (2009) (cover)
Left: Schematic of a p-GaN/i-InxGa1-xN/n-GaN heterojunction nanowire for photovoltaics. Right: Solar cell performance of a series of nanowire devices with systematically tuned InGaN composition under 1-sun illumination. Nano Lett. 9, 2183 (2009)
A flexible electrical recording from cells using nanowire transistor arrays. Proc. Natl. Acad. Sci. USA 106, 7309 (2009)
A new flexible approach for interfacing cells and nanowire field-effect transistors (NWFETs) is presented. Cells are cultured on thin polydimethylsiloxane (PDMS) sheets that are transferred to a NWFETs chip. Subsequently cells/PDMS are manipulated in space while their electroactivity is simultaneously monitored. Fig. 1, Proc. Natl. Acad. Sci. USA 106, 7309 (2009).
In this work, we exploit the unique capability of the bottom-up approach to fabricate NWFET arrays on flexible and transparent plastic substrates and interface these ultra-sensitive devices with spontaneously beating embryonic chicken hearts. Furthermore, we demonstrate that these novel device arrays enable multiplexed signal recording in a number of conformations as well as registration of devices to the heart surface. Nano Lett. 9, 914-918 (2009)
Novel axial and radial nanowire photovoltaic elements seen emerging from a scanning electron micrograph of silicon core-shell nanowires. Chem. Soc. Rev. 38, 16-24 (2009) (inside front cover)
Schematic and SEM image of a wet-etched single silicon nanowire with two serially integrated p-i-n diodes. After etching, the diode and tunnel junctions are clearly delineated. From Nano Lett. 8, 3456 (2008) (Figure 1)
Optical injection from the CdS semiconductor nanowire into the photonic-crystal waveguide. Nature Photon. 2, 622-626 (2008)
Above: Multi-quantum-well nanowire heterostructures for wavelength-controlled lasers. Right: Multi-color nanowire lasers. Nature Mater. 7, 701-706 (2008)
(a) Schematic of multiple FET array on a single ultralong p-SiNW. (b) Dark-field optical image of multiple FETs defined by electron beam lithography. The p-SiNW is horizontal in the image and the vertical lines crossing the NW correspond to S/D electrodes. Nano Lett. 8, 3004-3009 (2008)
Ge/Si heterostructure nanowire transistors with sub-100 nm channel and integrated high-kappa gate dielectric operate near the ballistic limit, and provide the best p-type FET performance to date. TOC, Nano Lett. 8, 925-930 (2008)
Blown bubble film approach for preparation of large-scale nanodevice arrays on wafers or plastics. Cover, J. Mater. Chem. 18, 728-734 (2008)
Schematic of a silver/amorphous silicon/crystalline silicon nonvolatile crossbar switch array Nano Lett. 8, 386 (2008)
SEM images of one-dimensional (a) and two-dimensional (c) crossbar switch arrays. The state of each crosspoint can be written or erased to ON or OFF and then read out sequentially (b, d) without cross-talk between different elements. Nano Lett. 8, 386 (2008)
Left: HRTEM of InAs/InP core/shell nanowire. Inset, cross-sectional schematic and corresponding band diagram. Right: Electron mobility of InAs/InP NW at different temperatures, the highest among reported 1D nanostructures. Nano Lett. 7, 3214-3218 (2007)
Ge/Si nanowire double dot device and demonstration of tunable interdot coupling. Fig.1, Nature Nanotechnol. 2, 622-625 (2007)
Left: Photograph of bubble expansion process. Upper right: 6-inch wafer scale blown bubble film containing uniform, well-aligned nanowires. Lower right: 8-inch wafer scale film containing ordered SWNTs. Nature Nanotech. 2, 372-377 (2007)
3D multifunctional electronics based on bottom-up multi-layer assembly of nanowires. Ten vertically stacked layers of Ge/Si core/shell multi-nanowire field effect transistors (FETs) were presented with uniform performance in sequential layers 1 through 10 of the 3D structure. Nano Lett. 7, 773-777 (2007)
Our silicon nanowire biosensor is on the cover of the Fifth Edition text, Chemistry: The Molecular Nature of Matter and Change, by Martin Silberberg. The cover image is designed by Michael Goodman. [larger image without type]
A hybrid structure consisting of a neuron with separate axon-nanowire (upper left branch) and dendrite-nanowire (upper right, lower left branches) interfaces demonstrates our ability to form multiple inputs and/or outputs to a single neuron. After stimulation at the soma (center), elicited signals can be measured at each of the cell-nanowire interfaces. Alternatively, the cell can be stimulated at the axon-nanowire interface with resulting signals measured at the two dendrite-nanowire connections. Science 313, 1100 (2006)
We show a single neuron (green), with an axon crossing an array of 50 nanowire devices (metallic contacts are yellow; individual nanowires are not visible) having 10 micron pitch. The speed, shape and time evolution of a signal can be mapped in real-time as it propagates along the axon. Individual nanowire elements can also be re-configured to simulate the axon or modulate an already propagating signal, providing our array with additional and unprecedented functionality. Science 313, 1100 (2006)
Left: A high angle annular dark field scanning transmission electron microscopy image of undoped GaN/AlN/AlGaN nanowire cross-section. Center: Schematic of top-gated nanowire field-effect transistor. Right: GaN/AlN/AlGaN nanowire heterostructure exhibits electron mobility of 3100 cm2/Vs at room temperature. Nano Lett. 6, 1468 (2006)
Top: Schematics of the nanowire photonic crystal with four engineered defects (left) and the nanowire racetrack microresonator (right). Bottom: Scanning electron microscope micrograph of the nanowire photonic crystal (left) and optical micrograph of the nanowire racetrack microresonator (right).
Scanning gate microscopy images of axial modulation doped silicon nanowires, in which the electronic properties are encoded during synthesis; the bright and dark regions reflect the variation in encoded electronic properties. Science 310, 1304 (2005)
III-nitride-based nanowire radial heterostructures as multicolor and high-efficiency light-emitting diodes.
Constant current STM image of a Au (111) surface with 4-5 single atomic steps and a screw dislocation. Image was taken in UHV at 78K with sample bias of -0.5V, tunneling current of 0.1nA, and scan size of 37nm.
Constant current STM image of three carbon nanotubes on a Au (111) surface; the herringbone reconstruction on the Au (111) surface is also visible. Image was taken in UHV at 78K, with a sample bias -1.5V, tunneling current of 0.2nA, and a scan size of 17nm.
High frequency nanowire ring oscillators on glass. Top: Optical images of nanowire ring oscillators fabricated on glass, and corresponding circuit diagram. The patterned nanowire film appears white in the image. Bottom: 11.7 MHz oscillation from a nanowire ring oscillator on glass. Nature 434, 1085 (2005)
Ballistic 1D transport in Ge/Si core/shell nanowire heterostructures. Proc. Natl. Acad. Sci. USA 102, 10046 (2005)
A transmission electron microscope (TEM) image of a cadmium sulfide nanowire.
A photoluminescence image of a cadmium sulfide nanowire.
The background shows a scanning electron microscopy image of the entangled silicon nanowires after the synthesis on the substrate. Using hierarchical organization strategy we developed, repeating arrays of crossed nanowires were made starting from these randomly oriented nanoscale building blocks. The hierarchy of the structures, including specific nanowire building block, nanowire pitch, nanowire orientation, array size, array orientation and array pitch, were controlled independently.
Nanowire solutions ready for assembly.
Glass (left) and plastic substrates resting against a solution of nanowires. The glass and plastic contain arrays of nanowire devices.
A flexible plastic substrate containing arrays of nanowire devices. The devices do not degrade under the effect of bending.
NiSi/Si nanowire heterostructure devices. [Nature 430, 61 (2004)]
Dark-field optical image of a NiSi/Si nanowire superlattice. [Nature 430, 61 (2004)]
GaN p-n crossed nanowire blue LED. Nano Lett. 3, 343 (2003)
Epitaxially grown p-type GaN nanowire array. Nano Lett. 3, 343 (2003).
Silicon nanowire address decoder. Science 302, 1377 (2003)