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	<title>oscillators &#8211; Science</title>
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	<title>oscillators &#8211; Science</title>
	<link>https://scienmag.com</link>
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		<title>DNA Instructions Turn Passive Microtubule Sheets Into Self-Morphing Active Matter</title>
		<link>https://scienmag.com/dna-instructions-turn-passive-microtubule-sheets-into-self-morphing-active-matter/</link>
		
		<dc:creator><![CDATA[Juliet Wilcox]]></dc:creator>
		<pubDate>Thu, 08 Oct 2026 23:37:08 +0000</pubDate>
				<category><![CDATA[Technology and Engineering]]></category>
		<category><![CDATA[active materials with internal regulation]]></category>
		<category><![CDATA[active matter]]></category>
		<category><![CDATA[autonomous cellular force generation]]></category>
		<category><![CDATA[bio-inspired soft matter]]></category>
		<category><![CDATA[bioinspired materials]]></category>
		<category><![CDATA[buckling instability]]></category>
		<category><![CDATA[cell-free gene expression]]></category>
		<category><![CDATA[cell-free gene expression in material design]]></category>
		<category><![CDATA[cell-free protein synthesis in materials]]></category>
		<category><![CDATA[DNA instructions for material behavior]]></category>
		<category><![CDATA[DNA-based active matter]]></category>
		<category><![CDATA[DNA-guided morphogenesis]]></category>
		<category><![CDATA[gene circuits]]></category>
		<category><![CDATA[kinesin]]></category>
		<category><![CDATA[microtubule self-organization]]></category>
		<category><![CDATA[microtubules]]></category>
		<category><![CDATA[molecular motors]]></category>
		<category><![CDATA[oscillators]]></category>
		<category><![CDATA[PRC1]]></category>
		<category><![CDATA[programmable active matter]]></category>
		<category><![CDATA[self-assembly]]></category>
		<category><![CDATA[self-morphing microtubule systems]]></category>
		<category><![CDATA[synthetic biological materials]]></category>
		<category><![CDATA[synthetic biology]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=250485</guid>

					<description><![CDATA[Researchers have embedded cell-free gene expression inside a microtubule network to create an active material whose flows, buckling, oscillations and arrests are programmed autonomously by synthetic DNA circuits.]]></description>
										<content:encoded><![CDATA[<p>Living cells are masters of self-transformation. They read genetic instructions, translate them into molecular motors and cross-linkers, and use those proteins to generate the forces that shape division, migration and morphogenesis. For decades, synthetic biologists and soft-matter physicists have tried to capture pieces of this magic in the laboratory, but a stubborn gap has remained: in virtually every reconstituted active-matter experiment, the concentrations of motors and cross-linkers are fixed the moment the sample is assembled. The material can be pushed around with light, chemical fuels or rapid mixing, but the regulatory logic always lives outside the material itself. A team led by Rochelle Silverman and Alexandra Tayar at the Weizmann Institute of Science, together with Vincent Noireaux&#8217;s group at the University of Minnesota and theorist Hillel Aharoni, has now closed that gap. Writing in Nature Materials, they report a microtubule-based active material whose mechanical behaviour is written in DNA and executed autonomously, without any external command after the experiment begins.</p>
<p>The heart of the platform is cell-free gene expression, or CFE, a cell-free transcription-translation system rebuilt from E. coli lysate that can synthesize proteins on demand outside any living cell. Rather than using CFE merely to make regulatory proteins that diffuse around a chamber, the researchers embedded the reaction directly inside a dense network of stabilized microtubules. DNA plasmids added to the mixture encode kinesin motors, and as the lysate churns out new kinesin, the motors cluster and attach to the microtubule scaffold. The newly synthesized proteins are not passive reporters of the gene circuit; they become the structural and force-generating components of the material itself. Activity, in other words, stops being a parameter chosen by the experimenter and becomes a dynamic variable governed by the underlying biochemical circuit.</p>
<p>The experimental choreography is striking to watch. At early times, when kinesin levels are still low, the microtubule sheet sits in the well as a mechanically quiescent, load-bearing gel with negligible internal motion. After roughly two hours, accumulated kinesin forms the multimeric clusters needed to slide adjacent filaments, and the flat sheet begins to deform. It first aligns, then buckles out of plane into a labyrinth of blister-like protrusions roughly 50 micrometres wide, spaced about 200 micrometres apart. About half an hour after buckling begins, the blisters fracture near their apexes, where deformation is largest, and the fragments reorganize into independently flowing active bundles that sustain turbulent-like extensile flows for up to eight hours, at speeds of roughly 0.3 to 0.5 micrometres per second. The material has, in effect, bootstrapped itself from a passive gel into self-mixing active turbulence using nothing but its own genetic instructions.</p>
<p>The buckling instability itself follows elegant physics. As kinesin accumulates, motor activity builds an in-plane compressive stress in the sheet. When that stress reaches a critical value scaling with the square root of the product of bending rigidity and gravitational loading, the flat sheet becomes unstable and wrinkles. The selected wavelength is set by the balance between the sheet&#8217;s bending rigidity and gravity, and the predicted value of roughly 360 micrometres, for a soft gel with an elastic modulus near one kilopascal and a thickness near ten micrometres, agrees well with the observed 150 to 200 micrometres. Crucially, this wavelength stayed essentially constant across all tested DNA concentrations, even though activation times varied enormously. DNA concentration, the authors conclude, does not simply tune how active the material becomes; it controls the trajectory through mechanical phase space by determining when successive active states become accessible.</p>
<p>That distinction became quantitative when the team varied the kinesin-encoding DNA from 0.1 to 13 nanomolar. Higher DNA concentrations advanced the onset of motion from about four hours down to about one hour and accelerated the rise to steady-state velocity, yet the maximal velocity saturated at roughly 0.5 micrometres per second above three nanomolar DNA, corresponding to an estimated tetrameric kinesin cluster concentration of about 0.7 micromolar. Notably, the onset of flow was not triggered at a fixed kinesin concentration: samples with less DNA accumulated more motor protein before flowing, while samples with more DNA flowed earlier at lower motor levels. The transition to buckling is therefore governed by the kinetics of motor production rather than a single critical threshold, and the mean blister width shrank fourfold, from about 80 to about 20 micrometres, as DNA concentration rose, following a power law consistent with an active length scale set by the competition between motor-generated stress and elastic resistance.</p>
<p>To show that gene-circuit architecture, not just expression level, can program mechanical behaviour, the researchers built three regulatory designs. The first was simple constitutive kinesin expression under a T7 promoter, which produced sustained active turbulence, with onset times tunable from about seven hours at low DNA to about 45 minutes at high DNA. The second added mechanical feedback by co-expressing PRC1, a natural microtubule-bundling protein, under a bacterial sigma-70 promoter. At low PRC1 DNA the material flowed as before; at intermediate concentrations buckling was followed by complete arrest; and at high concentrations the sheet pulsed, entering turbulence briefly before friction from excessive bundling overwhelmed the kinesin-generated stresses and froze the network. A single biochemical dial, the PRC1 DNA dose, thus switched the material between flowing, pulsed and arrested states.</p>
<p>The third and most spectacular circuit introduced delayed negative feedback, the same design principle that drives biological clocks. A kinesin-sigma-28 fusion protein activates expression of the bacteriophage lambda CI repressor, which in turn shuts off kinesin production, while the ssrA degradation tags on both proteins allow the endogenous ClpXP protease to clear them. Depending on the repressor DNA concentration, the material either reached steady turbulence, oscillated rhythmically with a period of about 30 minutes, or delivered a single pulse before arresting. The mechanical oscillations are a direct readout of the genetic oscillator: rising kinesin drives flow, delayed repression cuts it off, degradation resets the loop, and the cycle repeats. A material that pulses on its own schedule, encoded entirely in its DNA, is a genuinely new kind of synthetic object.</p>
<p>Tying everything together is a coarse-grained reaction-mechanics model that couples mRNA and protein dynamics to active flow. Transcription and translation rates, mRNA and protein lifetimes, and the regulatory function of each circuit feed into a mapping from motor and cross-linker abundance onto flow velocity. The model quantitatively reproduced all three experimental architectures, and its simulations revealed subtleties invisible to the microscope, such as the fact that velocity saturation in the constitutive case arises from the nonlinear motor-flow relationship rather than from any cessation of protein production, and that pulses and arrest in the PRC1 circuit emerge despite monotonically accumulating proteins, purely from mechanical coupling. The simulations also confirmed that without ClpXP-mediated degradation, the oscillator collapses back into the constitutive steady-flow solution, pinpointing protein turnover as the ingredient that unlocks oscillatory active matter.</p>
<p>Geometry supplies a second, complementary control layer. When the team confined the active sheet in 3D-printed channels between 100 and 500 micrometres wide, blister-like deformations aligned perpendicular to the channel axis, and their constrained length grew with channel width before saturating near 300 micrometres, while their width stayed near 50 micrometres, an intrinsic active length scale. Patterned ridges imposed anisotropic confinement that accelerated buckling and stretched deformations to millimetre scales along unconstrained directions, independent of ridge curvature. The broader implications reach toward self-morphing engineered materials, autonomous soft robots and artificial cells whose mechanics are programmed like software: gene circuits decide when distinct mechanical states emerge, geometry decides how they are spatially organized, and the material itself carries the instructions for its own transformation.</p>
<p><strong>Subject of Research:</strong> Genetically programmed self-morphing microtubule-based active matter driven by cell-free gene expression</p>
<p><strong>Article Title:</strong> Gene-driven self-morphing microtubule-based active matter</p>
<p><strong>Article References:</strong> Silverman, R., Zerbib, E., Garenne, D., Aharoni, H., Noireaux, V., &amp; Tayar, A. M. (2026). Gene-driven self-morphing microtubule-based active matter. <em>Nature Materials</em>. <a href="https://doi.org/10.1038/s41563-026-02767-4" rel="noopener noreferrer">https://doi.org/10.1038/s41563-026-02767-4</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s41563-026-02767-4" rel="noopener noreferrer">10.1038/s41563-026-02767-4</a></p>
<p><strong>Keywords:</strong> active matter, microtubules, kinesin, cell-free gene expression, synthetic biology, gene circuits, molecular motors, self-assembly, buckling instability, PRC1, oscillators, bioinspired materials</p>
]]></content:encoded>
					
		
		
		<post-id xmlns="com-wordpress:feed-additions:1">250485</post-id>	</item>
		<item>
		<title>Sound Chips Go the Distance: Silicon Nitride Meets Lithium Niobate for Low-Loss Phononic Circuits</title>
		<link>https://scienmag.com/sound-chips-go-the-distance-silicon-nitride-meets-lithium-niobate-for-low-loss-phononic-circuits/</link>
		
		<dc:creator><![CDATA[Denise Maddox]]></dc:creator>
		<pubDate>Thu, 08 Oct 2026 21:36:56 +0000</pubDate>
				<category><![CDATA[Technology and Engineering]]></category>
		<category><![CDATA[acoustic wave manipulation]]></category>
		<category><![CDATA[acoustic waveguides]]></category>
		<category><![CDATA[energy-efficient acoustic communication]]></category>
		<category><![CDATA[gigahertz-frequency sound routing]]></category>
		<category><![CDATA[hybrid photonic-phononic systems]]></category>
		<category><![CDATA[integrated circuits]]></category>
		<category><![CDATA[integrated phononic devices]]></category>
		<category><![CDATA[lithium niobate]]></category>
		<category><![CDATA[low-loss phononic circuits]]></category>
		<category><![CDATA[microwave acoustics]]></category>
		<category><![CDATA[nanoscale phononic waveguides]]></category>
		<category><![CDATA[oscillators]]></category>
		<category><![CDATA[phase noise]]></category>
		<category><![CDATA[phononic integrated circuits]]></category>
		<category><![CDATA[phononics]]></category>
		<category><![CDATA[piezoelectricity]]></category>
		<category><![CDATA[quality factor]]></category>
		<category><![CDATA[quantum information carriers]]></category>
		<category><![CDATA[quantum phononics]]></category>
		<category><![CDATA[ring resonators]]></category>
		<category><![CDATA[silicon nitride]]></category>
		<category><![CDATA[silicon nitride lithium niobate]]></category>
		<category><![CDATA[solid-state acoustic wave technology]]></category>
		<category><![CDATA[vibration-based information processing]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=249697</guid>

					<description><![CDATA[Researchers at Virginia Tech and the University of Virginia have built a low-loss phononic integrated circuit platform from silicon nitride on lithium niobate, achieving record-quality acoustic waveguides, couplers, resonators, and a 1-gigahertz oscillator with exceptionally low phase noise.]]></description>
										<content:encoded><![CDATA[<p>Sound, as strange as it may sound, is quietly becoming one of the most promising information carriers in modern technology. While photons dominate long-distance communication and electrons run the world of computing, acoustic waves—vibrations rippling through solid materials at microwave frequencies—offer a compact, stable, and remarkably energy-efficient middle ground. A research team led by Linbo Shao at Virginia Tech, working with colleagues at the University of Virginia, has now reported a major step forward for this emerging field: a low-loss phononic integrated circuit platform built from thin-film silicon nitride patterned on a lithium niobate substrate. The work, published in Communications Engineering, demonstrates that gigahertz-frequency sound can be routed, split, stored, and even turned into a self-sustaining oscillator on a chip with losses low enough to matter for both classical and quantum applications.</p>
<p>To appreciate why this matters, it helps to understand what a phononic integrated circuit, or PnIC, actually is. Just as photonic integrated circuits guide light through nanoscale channels, phononic circuits guide mechanical vibrations—phonons—through engineered waveguides. At gigahertz frequencies, these vibrations have wavelengths measured in mere hundreds of nanometers, roughly five orders of magnitude shorter than electromagnetic waves of the same frequency. That enormous shrinkage factor means acoustic devices can pack resonators, filters, and delay lines into a footprint far smaller than any radio-frequency electromagnetic equivalent. This is precisely why acoustic filters already sit inside nearly every smartphone, converting crowded radio signals into clean channels. The catch has been that most existing acoustic platforms force engineers to choose: they can have low-loss waveguides, or high-quality resonators, or efficient transducers, but rarely all of these on one chip.</p>
<p>The Virginia Tech and University of Virginia collaboration set out to break that trade-off. Their ideal platform, as described in the paper, should simultaneously support four building blocks: low-loss acoustic waveguides, high-quality-factor resonators, high-performance modulators, and efficient electromechanical transducers. The material pairing they chose is chemically and mechanically elegant. Lithium niobate is a ferroelectric crystal famous for its strong piezoelectric properties, meaning it converts electrical signals into mechanical motion—and back again—with exceptional efficiency. It also possesses large electro-optic and acoustic velocities that make it a favorite in modern integrated photonics. Silicon nitride, by contrast, is one of the lowest-loss optical materials known, forms ultrasmooth films, and is compatible with standard semiconductor foundry processes. By patterning thin-film silicon nitride directly on lithium niobate, the team created a hybrid structure in which each material does what it does best: lithium niobate drives and senses the vibrations, while the carefully shaped silicon nitride confines and directs them.</p>
<p>The headline performance metric of the new platform is the propagation frequency-quality factor product of its acoustic waveguides, which reached 4.22 × 10^13. In the world of resonant and wave-based systems, the quality factor, or Q, measures how many oscillation cycles a wave or resonator completes before its energy dissipates. Multiplying Q by frequency yields a figure of merit that is largely independent of scale, allowing fair comparison across platforms. A frequency-Q product above 10^13 places these acoustic waveguides in an elite class of coherent information carriers, comparable to the best optical waveguides in relative terms. Practically, it means that a gigahertz sound wave traveling through the team&#8217;s circuits retains its energy over distances long enough to build complex, multi-element circuits—delays, filters, interferometers—without the signal fading into heat. For quantum applications, where a single phonon must survive long enough to be manipulated and read out, such low loss is not a luxury but a prerequisite.</p>
<p>Waveguides alone do not make a circuit, however; engineers also need ways to split and combine acoustic signals with minimal waste. The team demonstrated directional couplers—devices in which two waveguides run close enough that vibrational energy gradually transfers from one to the other through evanescent coupling, the same physics that lets a vibrating tuning fork set a neighboring fork ringing. Their couplers achieved controllable power transfer at an insertion loss of just 3.5 dB. Insertion loss quantifies how much signal is lost simply by passing through a component, and every decibel counts when signals are weak or when photons and phonons must be conserved at the quantum level. A 3.5 dB figure means that roughly 55 percent of the acoustic power survives the coupling process, a level the authors identify as a key enabler for routing phonons between resonators, delay lines, and transducers on the same chip.</p>
<p>Storage is the third pillar, and here the platform delivered ring resonators with a loaded quality factor of up to 17,925. An acoustic ring resonator is a closed loop of waveguide in which sound circulates, resonating at frequencies whose wavelengths fit an integer number of times around the ring. The loaded Q includes the coupling losses to the outside world, not just the intrinsic material loss, making it the number that matters in real systems. A loaded Q near 18,000 at gigahertz frequencies corresponds to phonons persisting for microseconds—a long time on the scale of microwave electronics. Long-lived acoustic resonances are the heart of the spectral processing that makes radio-frequency acoustic filters so selective, and they are equally the heart of proposed quantum memories, where mechanical modes would buffer quantum states between optical photons or superconducting qubits.</p>
<p>The team then assembled these building blocks into a showcase application: a 1-gigahertz phononic oscillator built around one of their ring resonators. An oscillator is the metronome of electronics—a device that produces a perfectly periodic signal used to time everything from radio transmitters to radar systems to quantum logic gates. The best electronic oscillators achieve their stability by referencing a high-Q mechanical or electromagnetic resonance, and the new phononic oscillator leverages the platform&#8217;s 17,925 loaded Q to spectacular effect. It reached a phase noise of −159.0 dBc/Hz at a 100-kilohertz offset from the carrier. Phase noise describes the rapid, random fluctuations in an oscillator&#8217;s timing; lower is better, and the decibel scale here means the noise power is 159 billion times smaller than the carrier power within a one-hertz bandwidth at that offset. That figure rivals the performance of much bulkier, power-hungry microwave oscillators, in a device etched onto a chip.</p>
<p>The implications ripple outward across several fields at once. For microwave acoustics, the platform offers a path toward integrated radio-frequency processors that are smaller, cleaner, and more stable than today&#8217;s surface-acoustic-wave and bulk-acoustic-wave components, which typically rely on suspended or bulky geometries. For quantum phononics, low-loss gigahertz phonons are a sought-after resource: they can couple to superconducting qubits through piezoelectric transduction, interface with solid-state defects such as those in diamond or silicon carbide, and bridge to optical photons in hybrid quantum networks. Lithium niobate&#8217;s piezoelectricity makes that electromechanical link natural, while silicon nitride&#8217;s optical excellence makes the photonic link equally promising. The authors point to integrated hybrid systems combining phonons, photons, superconducting qubits, and solid-state defects as the long-term destination—and this platform is designed from the outset to host all of them.</p>
<p>The research was conducted with support from several major United States funding programs, including the Air Force Office of Scientific Research, the Defense Advanced Research Projects Agency&#8217;s OPTIM, SynQuaNon, and GRYPHON programs, and fabrication was performed at the Center for Nanophase Materials Sciences, a Department of Energy Office of Science user facility. The work also reflects a growing trend in which Virginia&#8217;s university ecosystem—through the Commonwealth Cybersecurity Initiative—invests in the intersection of quantum devices and secure communications. The paper, received in March 2026 and accepted in September 2026, is open access, allowing engineers and physicists worldwide to build on its results immediately.</p>
<p>What makes this demonstration genuinely exciting is its completeness. Many platform papers showcase a single impressive component; this one delivers waveguides, couplers, resonators, and a working oscillator, all on the same material system, all at gigahertz frequencies, and all with numbers that stand up against the best specialized devices in each category. The phonon, long treated as the awkward cousin of the photon, now has an integrated circuit platform worthy of its ambitions. If the trajectory of silicon photonics is any guide, the coming years could see these sound-based circuits shrink radar front ends, sharpen quantum sensors, and serve as the mechanical backbone of hybrid quantum machines—proof that sometimes the future of computing hums at a frequency we cannot hear, in a material we cannot see, on a chip smaller than a fingernail.</p>
<p><strong>Subject of Research:</strong> Low-loss gigahertz phononic integrated circuits on a silicon nitride–lithium niobate platform</p>
<p><strong>Article Title:</strong> Low-loss phononic integrated circuits based on a silicon nitride-lithium niobate platform</p>
<p><strong>Article References:</strong> Low-loss phononic integrated circuits based on a silicon nitride-lithium niobate platform. (n.d.). <a href="https://doi.org/10.1038/s44172-026-00795-1" rel="noopener noreferrer">https://doi.org/10.1038/s44172-026-00795-1</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s44172-026-00795-1" rel="noopener noreferrer">10.1038/s44172-026-00795-1</a></p>
<p><strong>Keywords:</strong> phononics, integrated circuits, silicon nitride, lithium niobate, acoustic waveguides, ring resonators, quality factor, oscillators, phase noise, quantum phononics, microwave acoustics, piezoelectricity</p>
]]></content:encoded>
					
		
		
		<post-id xmlns="com-wordpress:feed-additions:1">249697</post-id>	</item>
		<item>
		<title>Mathematicians Pin Down When Complex Oscillators Can Be Tuned at All</title>
		<link>https://scienmag.com/mathematicians-pin-down-when-complex-oscillators-can-be-tuned-at-all/</link>
		
		<dc:creator><![CDATA[Reid Dalton]]></dc:creator>
		<pubDate>Thu, 01 Oct 2026 12:34:29 +0000</pubDate>
				<category><![CDATA[Technology and Engineering]]></category>
		<category><![CDATA[biological oscillators regulation]]></category>
		<category><![CDATA[circadian clock control]]></category>
		<category><![CDATA[circadian rhythms]]></category>
		<category><![CDATA[complex networks]]></category>
		<category><![CDATA[complex oscillator tuning]]></category>
		<category><![CDATA[complex system behavior in biology]]></category>
		<category><![CDATA[dynamical systems]]></category>
		<category><![CDATA[frequency combs in precision metrology]]></category>
		<category><![CDATA[genetic circuit modulation]]></category>
		<category><![CDATA[genetic circuits]]></category>
		<category><![CDATA[inverse problems]]></category>
		<category><![CDATA[mathematical modeling of neural rhythms]]></category>
		<category><![CDATA[Nature Computational Science]]></category>
		<category><![CDATA[nonlinear dynamics]]></category>
		<category><![CDATA[optimization of neural and genetic oscillations]]></category>
		<category><![CDATA[oscillator modulatability criteria]]></category>
		<category><![CDATA[oscillators]]></category>
		<category><![CDATA[parameter identification]]></category>
		<category><![CDATA[parameter space analysis in biological systems]]></category>
		<category><![CDATA[repressilator]]></category>
		<category><![CDATA[spatiotemporal properties of oscillators]]></category>
		<category><![CDATA[synchronization]]></category>
		<category><![CDATA[synthetic biology]]></category>
		<category><![CDATA[theoretical framework for oscillator tuning]]></category>
		<guid isPermaLink="false">https://scienmag.com/?p=222702</guid>

					<description><![CDATA[A new mathematical framework establishes when complex oscillators can be uniquely tuned to multiple simultaneous targets, validated on electronic genetic circuits and data-driven inference.]]></description>
										<content:encoded><![CDATA[<p>Oscillators are everywhere. The circadian clocks that tell our bodies when to sleep and wake, the neural rhythms that coordinate movement, the genetic circuits that pulse inside dividing cells, and even the optical frequency combs that anchor modern precision metrology all share one defining feature: they repeat. But repeating is not enough. To keep these systems useful, scientists often need to steer them, nudging a biological clock toward a new period, reshaping the amplitude of a neural oscillation, or retuning a synthetic gene circuit so that its peaks and troughs land exactly where an experiment demands. A new study published in Nature Computational Science tackles a question that sounds deceptively simple but has long resisted a clean answer: given a complex oscillator and a list of desired spatiotemporal properties, when does a set of modulation parameters that achieves all of them actually exist, and when is it unique?</p>
<p>The research, led by Yutong Cai and Zhaoyue Zhong, with Zefeng Zhang, Bo-Wei Qin and senior author Wei Lin at Fudan University in Shanghai, introduces a rigorous mathematical treatment of what the authors call modulatability. Rather than asking how to push an oscillator toward a target behavior through trial and error, the team asked a more fundamental question about the geometry of the problem itself. If you want to impose several properties on an oscillating system at once, say a specific frequency, a specific amplitude, and a specific phase relationship across parts of a network, how many adjustable knobs do you need? Their central theoretical result is strikingly elegant: the local uniqueness of a solution is generally guaranteed when the number of free parameters equals the number of properties being targeted. Too few knobs and the problem is overconstrained, with most target combinations simply unreachable. Too many and solutions proliferate, making it hard to know which one a solver will find.</p>
<p>This dimensional matching principle may sound abstract, but it has immediate practical consequences. In the biological sciences, researchers routinely try to reprogram oscillators whose dynamics involve dozens of interacting variables. Synthetic biologists, for example, have spent two decades engineering genetic circuits such as the repressilator, a ring of three genes that repress one another in turn and thereby generate oscillating protein concentrations. Tuning such circuits to display both a desired period and a desired amplitude simultaneously has historically required laborious computational redesign or experimental screening. The Fudan team&#8217;s framework reframes the whole enterprise: instead of simulating trajectories forward and hoping to stumble on good parameters, the modulation task is treated as a property-based inverse problem, in which the desired properties are fixed and the equations are solved backward for the parameters that produce them.</p>
<p>The technical machinery behind the framework combines several ideas from dynamical systems and numerical analysis. The oscillatory trajectories of the system are represented through a Fourier expansion, allowing periodic solutions to be described by a finite set of coefficients once a truncation order is chosen. The desired properties, such as minima of particular protein activities or the period of the collective rhythm, are expressed as functions of these coefficients and of the system&#8217;s kinetic parameters. Solving for the parameters then becomes a root-finding problem in a space whose dimension is chosen deliberately to match the number of targets. The authors deploy Newton-type iterations to converge on solutions, and they use continuation strategies, stepping gradually through parameter space, to follow modulation paths even when the targets are far from the system&#8217;s natural behavior. Sweeps over system dimension, Fourier truncation order, number of targets, iteration tolerance, and continuation steps, reported in the paper&#8217;s extended data, map out how computational cost scales with each factor.</p>
<p>Crucially, the framework is not merely a simulation exercise. The team validated it on electronic analogs of genetic circuits, building hardware implementations of the repressilator concept in which voltages play the role of protein concentrations. From recorded voltage time courses alone, the researchers inferred the underlying parameters of the oscillating circuit and then modulated them to hit orthogonal targets, meaning goals that do not interfere with one another, such as independently shifting the period while holding amplitude fixed. The experiments included orthogonal period modulation tasks with two and with three simultaneous targets, and the inferred parameter distributions were tight and unimodal, suggesting that the inverse problem is well-posed in precisely the sense the theory predicts. This hardware demonstration matters because electronic circuits are a standard proving ground for ideas intended eventually for living cells, capturing the nonlinear feedback structure of genetic networks while remaining far easier to measure and perturb.</p>
<p>The data-driven side of the work is where the framework arguably delivers its most compelling numbers. In benchmark comparisons against baseline inference methods, the property-based approach achieved shorter runtimes and higher accuracy, a combination that is rare in inverse problems, where speed is usually bought at the cost of precision. The authors also demonstrated the framework on a model of an engineered Sir2-HAP negative feedback loop, a genetic oscillator linked to cellular longevity in yeast. In that system, low activity of the SIR2 and HAP proteins corresponds to a detrimental aging zone that the oscillating state variables pass through. By identifying a parameter set that up-regulates the minimal activities of both proteins, the framework showed in stochastic simulations, which added Ornstein-Uhlenbeck noise to eight kinetic terms, that the modulated oscillator avoids the aging zone more effectively, with distributions of minimum protein levels shifted upward across one hundred independent runs. It is a concrete illustration of how abstract parameter identification could translate into a design principle for extending cellular lifespan.</p>
<p>Networks add another layer of complexity, and the paper addresses it head-on. In one extended demonstration, the team applied their method to a FitzHugh-Nagumo neuronal network of one hundred nodes arranged on a randomly generated Barabasi-Albert topology, a structure mimicking the heterogeneous, hub-rich connectivity seen in many real systems. With fifty target nodes whose amplitudes needed adjustment, the researchers modulated random subsets of edges and measured how often the modulation succeeded while the network remained oscillatory. The results, summarized across many repeated trials, revealed how success rates depend on the balance between the number of targeted nodes and the number of edges available for modulation, with the equal-dimension condition again emerging as the natural dividing line. For anyone trying to control synchronization patterns in power grids, neural tissue, or coupled laser arrays, this kind of systematic map of when control is feasible is exactly the missing piece.</p>
<p>What makes the study resonate beyond applied mathematics is the sheer breadth of oscillatory phenomena it touches. The references span circadian medicine, the bioelectrical phase transition that patterns the first vertebrate heartbeats, collective oscillations emerging in massive human crowds, amplitude and frequency modulation of subthalamic beta oscillations in Parkinson&#8217;s disease, and synthetic oscillators designed to slow cellular aging. In each of these domains, the practical question is the same: which properties of the rhythm can be moved, and by touching which parameters? The modulatability framework offers a principled answer, replacing intuition with a dimension-counting criterion and replacing forward simulation with inverse problem solving. It also connects to a broader theoretical conversation about controlling complex networks, complementing earlier work on controllability, functional control of oscillator networks, and inverse problems for dynamic patterns in coupled systems.</p>
<p>The authors have made their work unusually accessible. The source code is publicly available on GitHub, with a frozen release archived on Zenodo, and a figure-to-script mapping document allows readers to reproduce individual results directly. Source data, including network topologies, modulation parameters, oscillatory trajectories, stochastic realizations, and the experimental voltage recordings from the electronic circuit, are deposited without restrictions. For a field where reproducibility of nonlinear dynamics can be notoriously difficult, this level of transparency lowers the barrier for other groups to test the framework on their own oscillators, whether biological, neural, mechanical, or photonic.</p>
<p>The larger significance of the work lies in its reframing. For years, the modulation of oscillators has been pursued through two parallel traditions, one statistical and one rooted in dynamical systems theory, each producing partial answers. By proving a general condition for when modulation parameters exist uniquely and packaging the insight into an efficient computational pipeline, the Fudan team has given both theorists and experimentalists a common language for a problem that cuts across biology, neuroscience, and engineering. If rhythms govern health, and disrupted oscillations are implicated in conditions from diabetes to psychiatric illness, then knowing exactly when and how a rhythm can be retuned is more than a mathematical curiosity. It is a step toward making oscillators, whether in a cell, a circuit board, or a brain, into things we can genuinely engineer.</p>
<p><strong>Subject of Research:</strong> Mathematical theory and computational framework for the modulatability of complex oscillators</p>
<p><strong>Article Title:</strong> Modulatability of complex oscillators</p>
<p><strong>Article References:</strong> Modulatability of complex oscillators. (n.d.). <a href="https://doi.org/10.1038/s43588-026-01050-5" rel="noopener noreferrer">https://doi.org/10.1038/s43588-026-01050-5</a></p>
<p><strong>Image Credits:</strong> AI Generated</p>
<p><strong>DOI:</strong> <a href="https://doi.org/10.1038/s43588-026-01050-5" rel="noopener noreferrer">10.1038/s43588-026-01050-5</a></p>
<p><strong>Keywords:</strong> oscillators, dynamical systems, inverse problems, complex networks, synchronization, genetic circuits, repressilator, circadian rhythms, parameter identification, nonlinear dynamics, Nature Computational Science, synthetic biology</p>
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