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Publications (334)
Atomic-scale defects behaving as two-level systems (TLSs) are crucial to the physics of modern quantum devices. Here, we study interactions between individual TLS defects and the mechanical vibrations of a nanoelectromechanical systems (NEMS) resonator. By applying a mechanical strain, we tune individual TLS onto resonance with the NEMS and observe...
Recent years have seen explosive growth in miniaturized sensors that can continuously monitor a wide variety of processes, with applications in healthcare, manufacturing, and environmental sensing. The time series generated by these sensors often involves abrupt jumps in the detected signal. One such application uses nanoelectromechanical systems (...
Sensing applications that utilize nanomechanical resonators require careful control of nonlinear effects in their eigenmodes to ensure robust measurement. While the effect of intra- and intermodal nonlinearities on the resonant frequencies of doubly clamped elastic beams have been widely studied using theory and experiment, commensurate studies on...
Background
The analysis of mass spectrometry-based quantitative proteomics data can be challenging given the variety of established analysis platforms, the differences in reporting formats, and a general lack of approachable standardized post-processing analyses such as sample group statistics, quantitative variation and even data filtering. We dev...
Due to its exceptional electronic and thermal properties, graphene is a key material for bolometry, calorimetry, and photon detection. However, despite graphene's relatively simple electronic structure, the physical processes responsible for the heat transport from the electrons to the lattice are experimentally still elusive. Here, we measure the...
In this chapter a general vision of the issues faced while performing measurements of nanomechanical resonators is presented. Different amplitude noise sources are analyzed: thermomechanical noise, electrical noise (Johnson, 1∕f, shot noise), and amplifier noise, to later define the Allan variance for specific frequency tracking schemes and how it...
The efficient transduction of nanomechanical resonators is quintessential for any practical application. In the context of this book, transduction refers to the translation of mechanical motion to an electrical signal and vice versa for detection and actuation, respectively. In this chapter the most common underlying physical transducing mechanisms...
A change of mass or temperature, or an applied force, causes a response of a mechanical resonator. The response can, e.g., be a change in frequency or vibrational amplitude. The responsivity of a mechanical resonator is the linear slope of the response to a particular stimulant. In case of a sensor application, the responsivity to the input paramet...
The mechanics of nanomechanical resonators can be described by a lumped-element model. In this chapter, linear, coupled, and nonlinear damped and driven resonators are discussed by means of lumped-element models. Additionally, the phenomenon of parametric amplification is introduced. Such simplified models with a single degree of freedom are the ba...
The quality factor defines the rate with which a nanomechanical resonator dissipates energy. Low energy loss, i.e., a high quality factor, is desirable for most applications of nanomechanical resonators. In this chapter, the three main sources of energy loss in nanomechanical resonators are presented. Energy can be lost (i) to the surrounding mediu...
Nanomechanical resonators are continuum mechanical structures, such as beams, strings, plates, or membranes. In this chapter the eigenmodes as well as geometrical nonlinearities of such ideal lossless continuum mechanical structures are estimated by simple analytical models. Finally, the transition of individual continuum mechanical normal modes to...
Due to its exceptional electronic and thermal properties, graphene is a key material for bolometry, calorimetry, and photon detection. However, despite graphene's relatively simple electronic structure, the physical processes responsible for the transport of heat from the electrons to the lattice are experimentally still elusive. Here, we measure t...
Implantable silicon neural probes with integrated nanophotonic waveguides can deliver patterned dynamic illumination into brain tissue at depth. Here, we introduce neural probes with integrated optical phased arrays and demonstrate optical beam steering in vitro. Beam formation in brain tissue is simulated and characterized. The probes are used for...
Integrated neurophotonics can surmount limitations of existing methodologies to enable fast and dense large-scale functional imaging of neuronal activity from within the brain itself. Implantable lens-less nanophotonic arrays yield cellular resolution at arbitrary brain depths.
Synaptic transmission via neurochemical release is the fundamental process that integrates and relays encoded information in the brain to regulate physiological function, cognition, and emotion. To unravel the biochemical, biophysical, and computational mechanisms of signal processing, one needs to precisely measure the neurochemical release dynami...
Implantable silicon neural probes with integrated nanophotonic waveguides can deliver patterned dynamic illumination into brain tissue at depth. Here, we introduce neural probes with integrated optical phased arrays and demonstrate optical beam steering in vitro. Beam formation in brain tissue was simulated and characterized. The probes were used f...
We experimentally demonstrate that highly structured distributions of work emerge during even the simple task of erasing a single bit. These are signatures of a refined suite of time-reversal symmetries in distinct functional classes of microscopic trajectories. As a consequence, we introduce a broad family of conditional fluctuation theorems that...
We demonstrate implantable neural probes with integrated silicon nitride optical phased arrays (OPAs) fabricated on 200mm wafers for wavelengths near 480nm. A free-propagation slab enables the emission of a single steerable beam from an OPA.
We propose a new paradigm for dense functional imaging of brain activity to surmount the limitations of present methodologies. We term this approach “integrated neurophotonics”; it combines recent advances in microchip-based integrated photonic and electronic circuitry with those from optogenetics. This approach has the potential to enable lens-les...
A new modality Photonic probes record fluorescent signals by using arrays of light emitters and detectors embedded in neural tissue. Neither the emitted nor collected light fields are focused. Instead, in proposed configurations, hundreds of emitters will form rapid sequences of structured illumination patterns—providing sufficient spatial and temp...
Significance: Light-sheet fluorescence microscopy (LSFM) is a powerful technique for high-speed volumetric functional imaging. However, in typical light-sheet microscopes, the illumination and collection optics impose significant constraints upon the imaging of non-transparent brain tissues. We demonstrate that these constraints can be surmounted u...
Significance
Light-sheet fluorescence microscopy is a powerful technique for high-speed volumetric functional imaging. However, in typical light-sheet microscopes, the illumination and collection optics impose significant constraints upon the imaging of non-transparent brain tissues. Here, we demonstrate that these constraints can be surmounted usi...
Photonic probes record fluorescent signals by using arrays of light emitters and detectors embedded in neural tissue. Neither the emitted nor collected light fields are focused. Instead, in proposed configurations, hundreds of emitters will form rapid sequences of structured illumination patterns—providing sufficient spatial and temporal differenti...
This paper presents a device for time-gated fluorescence imaging in the deep brain, consisting of two on-chip laser diodes and 512 single-photon avalanche diodes (SPADs). The edge-emitting laser diodes deliver fluorescence excitation above the SPAD array, parallel to the imager. In the time domain, laser diode illumination is pulsed and the SPAD is...
We implement a thermal-fluctuation-driven logical bit reset on a superconducting flux logic cell. We show that the logical state of the system can be continuously monitored with only a small perturbation to the thermally activated dynamics at 500 mK. We use the trajectory information to derive a single-shot estimate of the work performed on the sys...
We present passive, visible light silicon nitride waveguides fabricated on ≈ 100 µm thick 200 mm silicon wafers using deep ultraviolet lithography. The best-case propagation losses of single-mode waveguides were ≤ 2.8 dB/cm and ≤ 1.9 dB/cm over continuous wavelength ranges of 466-550 nm and 552-648 nm, respectively. In-plane waveguide crossings and...
We present an implantable single-photon shank-based imager, monolithically integrated onto a single CMOS IC. The imager comprises of 512 single-photon avalanche diodes distributed along two shanks, with a 6-bit depth in-pixel memory and an on-chip digital-to-time converter. To scale down the system to a minimally invasive form factor, we substitute...
Weak electron-phonon interaction in metals at low temperatures forms the basis of operation for cryogenic hot-electron bolometers and calorimeters. Standard power laws, describing the heat flow in the majority of experiments, have been identified and derived theoretically. However, a full picture encompassing experimentally relevant effects such as...
Weak electron-phonon interaction in metals at low temperatures forms the basis of operation for cryogenic hot-electron bolometers and calorimeters. Standard power laws, describing the heat flow in the majority of experiments, have been identified and derived theoretically. However, a full picture encompassing experimentally relevant effects such as...
We implement a thermal-fluctuation driven logical bit reset on a superconducting flux logic cell. We show that the logical state of the system can be continuously monitored with only a small perturbation to the thermally activated dynamics at 500 mK. We use the trajectory information to derive a single-shot estimate of the work performed on the sys...
We propose a new mechanism of friction in resonantly driven vibrational systems. The form of the friction force follows from the time- and spatial-symmetry arguments. We consider a microscopic mechanism of this resonant force in nanomechanical systems. The friction can be negative, leading to the onset of self-sustained oscillations of the amplitud...
We experimentally demonstrate that highly structured distributions of work emerge during even the simple task of erasing a single bit. These are signatures of a refined suite of time-reversal symmetries in distinct functional classes of microscopic trajectories. As a consequence, we introduce a broad family of conditional fluctuation theorems that...
We report on the first imaging and visualization of the multimode resonant behaviors of aluminum nitride (AlN) piezoelectric nanomembrane resonators, by exploiting a spectromicroscopy technique based on scanning laser interferometry. High-frequency multimode vibrations (up to 33MHz) with quality (Q) factors up to ~8500 are observed in the AlN nanom...
Gas Chromatography (GC) is routinely used in the laboratory to temporally separate chemical mixtures into their constituent components for improved chemical identification. This paper will provide a overview of more than twenty years of development of one-dimensional field-portable micro GC systems, highlighting key experimental results that illust...
We demonstrate the first implantable nanophotonic neural probes with integrated silicon nitride phased arrays. Coherent beam-steering is achieved in brain tissue by wavelength tuning. Beam profiles, optogenetic stimulation, and functional imaging are validated in vitro.
We present implantable silicon neural probes with nanophotonic waveguide routing networks and grating emitters for light sheet imaging. Fluorescein beam profiles, fluorescent bead imaging, and fluorescence brain imaging in vivo are presented.
We propose a new mechanism of friction in resonantly driven vibrational systems. The form of the friction force follows from the time- and spatial-symmetry arguments. We consider a microscopic mechanism of this resonant force in nanomechanical systems. The friction can be negative, leading to an instability of forced vibrations of a nanoresonator a...
A small, consumable-free, low-power, ultra-high-speed comprehensive GCxGC system consisting of microfabricated columns, NanoElectroMechanical System (NEMS) cantilever resonators for detection, and a valve-based stop-flow modulator is demonstrated. The separation of a highly polar 29-component mixture covering a boiling point range of 46 to 253 °C o...
Quickly exploring weakly coupled oscillators
Synchronizing oscillators have been useful models for exploring coupling in dynamic systems. However, many macroscopic platforms such as pendula evolve on slow time scales, which can limit the observation of states that emerge after many cycles. Matheny et al. fabricated a ring of eight nanoelectromechan...
Optical functional neural imaging has revolutionized neuroscience with optical reporters that enable single-cell-resolved monitoring of neuronal activity in vivo. State-of-the-art microscopy methods, however, are fundamentally limited in imaging depth by absorption and scattering in tissue even with the use of the most sophisticated two-photon micr...
We report on a novel aluminum nitride (AlN) resonant nanoelectromechanical systems (NEMS) approach to realizing an electrically tunable nonreciprocal isolator by exploiting nonlinear parametric frequency conversion and efficient mechanical amplification in a radio-frequency (RF) AlN membrane NEMS resonator. The isolator is constructed by combining...
One of the main challenges to overcome to perform nanomechanical Mass Spectrometry (NEMS-MS) analysis in a practical time frame stems from the size mismatch between the analyte beam and the extremely small nanomechanical detector area. We report here the demonstration of NEMS-MS with arrays of 20 individually addressed nanomechanical resonators whe...
The locust is a widely used animal model for studying sensory processing and its relation to behavior. Due to the lack of genomic information, genetic tools to manipulate neural circuits in locusts are not yet available. We examined whether Semliki Forest virus is suitable to mediate exogenous gene expression in neurons of the locust optic lobe. We...
Locust is a widely used animal model for studying sensory processing and its relation to behavior. Due to the lack of genomic information, genetic tools to manipulate neural circuits in locusts are not yet available. We examined whether Semliki Forest virus is suitable to mediate exogenous gene expression in neurons of the locust optic lobe. We sub...
We provide here a demonstration of 12−μm-pitch nanoelectromechanical resonant infrared sensors with fully integrated capacitive transduction. A low-temperature fabrication process is used to manufacture torsional resonator arrays. An H-shaped pixel with 9−μm-long nanorods and (250×30)−nm2 cross section is designed to provide high thermal response w...
The mass measurement of single molecules, in real time, is performed routinely using resonant nanomechanical devices. This approach models the molecules as point particles. A recent development now allows the spatial extent, and indeed image, of the adsorbate to be characterized using multi-mode measurements [M. S. Hanay et al., Nature Nanotechnol....
Control of the global parameters of complex networks has been explored experimentally in a variety of contexts. Yet, the more difficult prospect of realizing arbitrary network architectures, especially analog physical networks, that provide dynamical control of individual nodes and edges has remained elusive. It also proves challenging to measure a...
Resonant Nanoelectromechanical Systems (NEMS) have generated an enormous interest over the last 15 years, driven by a combination of fundamental questions and practical needs. The combination of relatively high frequencies, high quality factors and small masses make them ideal for a plethora of sensing applications. As an example, it has been possi...
Optogenetic methods developed over the past decade enable unprecedented optical activation and silencing of specific neuronal cell types. However, light scattering in neural tissue precludes illuminating areas deep within the brain via free-space optics; this has impeded employing optogenetics universally. Here, we report an approach surmounting th...
Computations in brain circuits involve the coordinated activation of large populations of neurons distributed across brain areas. However, monitoring neuronal activity in the brain of intact animals with high temporal and spatial resolution has remained a technological challenge. Here we address this challenge by developing dense, three-dimensional...
We present a microscopic theory of nonlinear damping and dephasing of low-frequency eigenmodes in nano- and micro-mechanical systems. The mechanism of the both effects is scattering of thermally excited vibrational modes off the considered eigenmode. The scattering is accompanied by energy transfer of $2\hbar\omega_0$ for nonlinear damping and is q...
We present a microscopic theory of nonlinear damping and dephasing of low-frequency eigenmodes in nano- and micro-mechanical systems. The mechanism of the both effects is scattering of thermally excited vibrational modes off the considered eigenmode. The scattering is accompanied by energy transfer of $2\hbar\omega_0$ for nonlinear damping and is q...
A change of mass or temperature, or an applied force causes a response of a mechanical resonator. The response can, e.g., be a change in frequency or vibrational amplitude. The responsivity of a mechanical resonator is the linear slope of the response to a particular stimulant. In case of a sensor application, the responsivity to the input paramete...
Max Planck used to say that the only things that exist are those that can be measured. In this chapter a general vision of the issues faced while performing measurements of nanomechanical resonators is presented. Different noise sources are analyzed: thermomechanical noise, electrical noise (Johnson, 1∕f, shot noise), and amplifier noise; to later...
Nanomechanical resonators are continuum mechanical structures, such as beams, strings, plates, or membranes. In this chapter the eigenmodes of such ideal lossless continuum mechanical structures are estimated by simple analytical models. Specific resonance modes of a damped continuum mechanical structure are best described by an effective lumped-el...
The quality factor defines the rate with which a nanomechanical resonator dissipates energy. Low energy loss, i.e. a high quality factor, is desirable for most applications of nanomechanical resonators. In this chapter, the three main sources of energy loss in nanomechanical resonators are presented. Energy can be lost (1) to the surrounding medium...
The efficient transduction of nanomechanical resonators is quintessential for any practical application. In the context of this book, transduction refers to the translation of mechanical motion to an electrical signal and vice versa for detection and actuation, respectively. In this chapter the most common underlying physical transducing mechanisms...
We present visible-wavelength photonic probes that implement WDM method for delivery of complex illumination patterns with cellular-scale spatial resolution deep within brain tissue. Neuron activation is verified by extracellular electrical recordings, and by two-photon functional imaging.
This authoritative book introduces and summarizes the latest models and skills required to design and optimize nanomechanical resonators, taking a top-down approach that uses macroscopic formulas to model the devices. The authors cover the electrical and mechanical aspects of nano electromechanical system (NEMS) devices. The introduced mechanical m...
We propose the creation of a national network of neurotechnology centers to enhance and accelerate the BRAIN Initiative and optimally leverage the effort and creativity of individual laboratories involved in it. As "brain observatories," these centers could provide the critical interdisciplinary environment both for realizing ambitious and complex...
Frequency stability is key to performance of nanoresonators and their
applications. This stability is thought to reach a limit with the resonator's
ability to resolve thermally-induced vibrations. Although measurements and
predictions of resonator stability usually disregard fluctuations in the
mechanical frequency response, these fluctuations have...
Mass sensing with nanoelectromechanical systems has advanced significantly during the last decade. With nanoelectromechanical systems sensors it is now possible to carry out ultrasensitive detection of gaseous analytes, to achieve atomic-scale mass resolution and to perform mass spectrometry on single proteins. Here, we demonstrate that the spatial...
In this paper we propose using Array Waveguide Gratings (AWGs), working in the visible range, in order to implement the technique of Wavelength-Division-(de)Multiplexing for multi-point stimulation of deep-brain neurons. We've developed a CMOS compatible fabrication process and fabricated two sets of AWGs, working in the red and blue wavelengths. E...
I describe a new paradigm for functional imaging that surmounts limitations of free-space optics - based on integrated nanophotonics, to distribute an ultraminiaturized imager within the brain; and optogenetics, to transduce neural signals into the optical domain
Doubly-clamped nanowire electromechanical resonators that can be used to generate parametric oscillations and feedback self-sustained oscillations. The nanowire electromechanical resonators can be made using conventional NEMS and CMOS fabrication methods. In very thin nanowire structures (sub-micron-meter in width), additive piezoresistance pattern...
A microfluidic embedded nanoelectromechanical system (NEMs) force sensor provides an electrical readout. The force sensor contains a deformable member that is integrated with a strain sensor. The strain sensor converts a deformation of the deformable member into an electrical signal. A microfluidic channel encapsulates the force sensor, controls a...
Surface-initiated polymerization has been used to grow thick, uniform poly(methyl methacrylate) (PMMA) films on nanocantilever sensors. Cantilevers with these coatings yielded significantly greater sensitivity relative to bare devices as well as relative to devices that had been coated with dropcast polymer films. The devices with surface-initiated...
An embodiment of the invention provides a neural probe containing a plurality of nanoscale recording electrodes. The recording electrodes have a width of 1 micron or less and a distance between adjacent recording electrodes is 10 microns or less. Another embodiment of the invention provides a neural probe comprising a plurality of microfabricated r...
We investigate the synchronization of oscillators based on anharmonic nanoelectromechanical resonators. Our experimental implementation allows unprecedented observation and control of parameters governing the dynamics of synchronization. We find close quantitative agreement between experimental data and theory describing reactively coupled Duffing...
Rarefied gas flows generated by resonating nanomechanical structures pose a significant challenge to theoretical analysis and physical interpretation. The inherent noncontinuum nature of such flows obviates the use of classical theories, such as the Navier-Stokes equations, requiring more sophisticated physical treatments for their characterization...
A method of screening one or more cells is described; the method includes: (i) providing one or more cells to a nanoelectromechanical system (NEMS) force sensor; (ii) applying at least one reagent to the one or more cells; and (iii) observing a response of the one or more cells to the reagent with the force sensor, thereby screening the one or more...
In its most basic form an oscillator consists of a resonator driven on resonance, through feedback, to create a periodic signal sustained by a static energy source. The generation of a stable frequency, the basic function of oscillators, is typically achieved by increasing the amplitude of motion of the resonator while remaining within its linear,...
Neuroscience is at a crossroads. Great effort is being invested into deciphering specific neural interactions and circuits. At the same time, there exist few general theories or principles that explain brain function. We attribute this disparity, in part, to limitations in current methodologies. Traditional neurophysiological approaches record the...
We investigate use of nanomechanical torsional resonators for frequency-shift-based infrared (IR) thermal sensing. Nanoscale torsion rods, ∼1 μm long and 50-100 nm in diameter, provide both extraordinary thermal isolation and excellent angular displacement and torque sensitivities, of order ∼10-7 rad·Hz-1/2 and ∼10-22 (N·m) Hz-1/2, respectively. Fu...
Neuroscientists have made impressive advances in understanding the microscale function of single neurons and the macroscale activity of the human brain. One can probe molecular and biophysical aspects of individual neurons and also view the human brain in action with magnetic resonance imaging (MRI) or magnetoencephalography (MEG). However, the mec...
A parametric feedback oscillator includes a resonator which has at least one transduction element and at least one electromechanical resonating element. The resonator is configured to accept as input a parametric excitation signal at a frequency 2ω0 and to provide a resonating output signal at a frequency ω0. A cascaded feedback path in any electri...
A neural probe includes at least one shaft, at least one first electrode disposed on a first side of the at least one shaft, and at least one second electrode disposed on a second side of the at least one shaft. The at least one second electrode is separately addressable from the at least first electrode.
Euler-Bernoulli beam theory is widely used to successfully predict the linear
dynamics of micro- and nano-cantilever beams. However, its capacity to
characterize the nonlinear dynamics of these devices has not yet been
rigorously assessed, despite its use in nanoelectromechanical systems
development. In this article, we report the first highly cont...
A system, device, method, and apparatus provide the ability to wire a voltage sensitive device to a nanoelectromechanical system (NEMS) resonator. A voltage sensitive device is configured to detect one or more voltage signals and output one or more electrical potentials in real-time. An array of piezoelectric NEMS resonators (with each resonator tu...
We demonstrate an analytical method for calculating the phase sensitivity of a class of oscillators whose phase does not affect the time evolution of the other dynamic variables. We show that such oscillators possess the possibility for complete phase noise elimination. We apply the method to a feedback oscillator which employs a high Q weakly nonl...
The effect of surface stress on the stiffness of cantilever beams remains an outstanding problem in the
physical sciences. While numerous experimental studies report significant stiffness change due to surface
stress, theoretical predictions are unable to rigorously and quantitatively reconcile these observations. In
this Letter, we present the fir...
We demonstrate an analytical method for calculating the phase sensitivity of a class of oscillators whose phase does not affect the time evolution of the other dynamic variables. We show that such oscillators possess the possibility for complete phase noise elimination. We apply the method to a feedback oscillator which employs a high Q weakly nonl...
Nanoelectromechanical systems (NEMS) resonators can detect mass with exceptional sensitivity. Previously, mass spectra from several hundred adsorption events were assembled in NEMS-based mass spectrometry using statistical analysis. Here, we report the first realization of single-molecule NEMS-based mass spectrometry in real time. As each molecule...
We introduce a new method for reducing phase noise in oscillators, thereby improving their frequency precision. The noise reduction is realized by a passive device consisting of a pair of coupled nonlinear resonating elements that are driven parametrically by the output of a conventional oscillator at a frequency close to the sum of the linear mode...
The function of neural circuits is an emergent property that arises from the coordinated activity of large
numbers of neurons. To capture this, we propose launching a large-scale, international public effort, the Brain
Activity Map Project, aimed at reconstructing the full record of neural activity across complete neural circuits.
This technologica...
We have developed arrays of nanomechanical systems (NEMS) by large-scale integration, comprising thousands of individual nanoresonators with densities of up to 6 million NEMS per square centimeter. The individual NEMS devices are electrically coupled using a combined series-parallel configuration that is extremely robust with respect to lithographi...
