Hans Jenny’s experiments MUSIC & BACTERIA - the arragement of patterns ABSTRACT
If SOUND can influence MATTER, could ACOUSTIC STIMULATION become a tool for interacting with MICROORGANISMS in a controlled way?
“Sound is mechanical vibration. Bacteria are physical structures. Cymatics is the science that makes sound visible — it shows that when sound meets a fluid surface, it automatically prints a pattern of energy: this energy is expressed in antinodes (regions of high pressure) and nodes (regions of low pressure). These vibrational patterns are physical principles that operate across scales, from quantum systems to animal morphogenesis to cortical activity in the human brain. Therefore, they are not only an aesthetical phemonoma.
If SOUND can influence MATTER, could ACOUSTIC STIMULATION become a tool for interacting with MICROORGANISMS in a controlled way?
“Sound is mechanical vibration. Bacteria are physical structures. Cymatics is the science that makes sound visible — it shows that when sound meets a fluid surface, it automatically prints a pattern of energy: this energy is expressed in antinodes (regions of high pressure) and nodes (regions of low pressure). These vibrational patterns are physical principles that operate across scales, from quantum systems to animal morphogenesis to cortical activity in the human brain. Therefore, they are not only an aesthetical phemonoma.
This project investigates whether those same physical principles can be used to control the spatial organization of living organisms and produce a patterned guided bio-material. The central innovation is bio-leather with sound-designed patterns using specific acoustic frequencies to guide bacterial spatial organization during growth, producing biomaterials whose structure and color emerge directly from the physics of sound influence.
The central hypothesis is twofold:
First, that controlled acoustic frequencies in the 20–500 Hz range will generate measurable and reproducible spatial reorganization of bacterial colonies in liquid media by generating Faraday waves — standing wave patterns that create deterministic hydrodynamic flows redistributing organisms toward antinodal zones.
The project is organized into three aims.
AIM 1 validates acoustic patterning of: a) E. coli-aeBlue and K. xylinus in Petri dish experiments using HS liquid medium and sodium alginate. b) E. coli-aeBlue and B.subtilis in Petri dish experiments using an Alginate liquid medium + CaCl2.
AIM 2 scales the results, adds mini-scaffolds, and tests directional movement on X and Z axes.
AIM 3 applies the accumulated knowledge to produce a three-dimensional self-growing sculpture guided by sound and nutrient gradients.
Introduction
PROJECT AIMS
Aim 1 — Experimental Aim
The first aim of this project is to validate sound-induced spatial patterning in E. coli, K. xylinus and B. subtilis using chromoprotein expression and cellulose architecture as visual reporters, across two substrates: HS liquid medium and sodium alginate.
This aim is organized as a conditional experimental matrix. Each combination of organism and substrate is tested first without sound to establish the biological baseline, then with selected acoustic frequencies. Steps advance only when the previous step produces a result differentiable from the no-sound control. Two parallel tracks are pursued:
the HS medium track K. xylinus + E. coli-aeBlue
the alginate track E. coli-aeBlue + B. subtilis
Category
Relevant Methods and Resources
Genetic Design
Benchling for circuit design; iGEM Parts Registry (BBa_J23101, BBa_B0034, BBa_K864401, BBa_B0015); pUC19 vector; Addgene #117846 as reference
Acoustic Simulation
Falstad (falstad.com/ripple), a free browser-based 2D wave propagation simulator for node/antinode mapping by frequency. It provides an estimate of how patterns form in the medium.
Transformation
Chemical heat-shock transformation of E. coli DH5α
ImageJ for densitometry, FFT analysis, and OD600 growth curves measured every 6 h
Experimental plan, step by step:
a. Track A — HS medium:
Experiment
Condition
Purpose / Hypothesis
Expected Outcome
1a
K. xylinus + HS medium (no sound)
Baseline cellulose film formation. Documents natural pellicle architecture, thickness, and distribution. Static culture for 5–7 days at 28–30°C.
Natural cellulose pellicle morphology and thickness distribution.
1b
K. xylinus + HS medium + selected frequencies
Tests whether acoustic stimulation modifies cellulose architecture. Based on Zhang et al. (2025), SAW stimulation increases K. xylinus production by 14–73%. Explores Faraday wave effects at lower frequencies (50–500 Hz).
Spatial patterning of cellulose thickness and altered pellicle architecture.
2a
E. coli-aeBlue + HS medium (no sound)
Baseline chromoprotein expression experiment.
Uniform distribution of blue chromoprotein expression.
2b
E. coli-aeBlue + HS medium + selected frequencies
Tests whether sound concentrates E. coli in nodal/antinodal zones. Hong et al. (2020) demonstrated that E. coli biofilms can replicate Faraday wave geometries after 24 h vibration.
≥20% color density difference between maximum and minimum accumulation zones.
3a
K. xylinus + HS medium + E. coli-aeBlue co-culture (no sound)
Tests whether both organisms can coexist under shared culture conditions. Main challenge: pH compatibility between species.
Determination of a compromise medium pH allowing partial coexistence and growth of both organisms.
3b
K. xylinus + HS medium + E. coli-aeBlue + selected frequencies
KEY TEST. Conducted only if Experiments 1b and 3a succeed. Evaluates whether acoustic stimulation spatially organizes both cellulose deposition and bacterial pigmentation.
Thicker and more intensely blue cellulose at antinodes; thinner, more transparent, and flexible cellulose at nodes. Acoustic stimulation may also improve nutrient flow toward concentrated bacterial regions.
b. Track B — Alginate medium:
Note: B. subtilis and E. coli cannot be co-cultured simultaneously because B. subtilis produces antimicrobial peptides (iturins, surfactins) that kill E. coli. The solution relies on sequential cultures at different times using different frequencies, so wave patterns do not coincide, and cultures do not interfere.
Experiment
Condition
Purpose / Hypothesis
Expected Outcome
1a
Alginate semi-liquid + frequencies (no bacteria)
Abiotic validation of Faraday pattern formation in alginate substrate.
Formation of stable wave-based patterns in the alginate medium without biological components.
2a
Alginate + E. coli-aeBlue (no sound)
Baseline chromoprotein distribution in alginate substrate.
Uniform blue color distribution throughout the gel matrix.
2b
Alginate + E. coli-aeBlue + frequencies + delayed CaCl₂
Tests whether Faraday wave patterns can be “frozen” into alginate during gelation. CaCl₂ is applied from the edges while vibration continues during the first 60 s of gelation.
Spatially patterned blue pigmentation captured within the gel structure.
3a
Alginate + B. subtilis (no sound)
Baseline biofilm texture formation by B. subtilis.
Natural morphological texture and biofilm growth patterns.
3b
Alginate + B. subtilis + frequencies + delayed CaCl₂
Tests whether acoustic stimulation modifies and captures B. subtilis texture organization in alginate.
Patterned morphological textures corresponding to vibration-induced wave geometry.
4a
Alginate + E. coli-aeBlue + frequency X + CaCl₂, followed by B. subtilis + frequency Y + CaCl₂
Sequential dual-patterning experiment performed only if Experiments 2b and 3b succeed. Evaluates whether two distinct biological patterning systems can coexist within the same bio-leather material.
Bio-leather with dual spatial organization: blue pigmentation from E. coli generated at frequency X and morphological texture from B. subtilis generated at frequency Y.
Critical protocol:
Thicker layers do not produce marked biofilm patterns (Hong et al. 2020).
Faraday wave frequency = excitation frequency ÷ 2.
Amplitude must be above the Faraday instability threshold and below the turbulence threshold because outside this window, no patterns form.
Aim 1 - Sound and cultures
Aim 2 — Development Aim
The next step following a successful AIM 1 is to scale the winning organism-substrate combinations. Then it would be to test whether sound can create directional movement and volumetric organization of bacteria, extending from 2D flat patterning to 3D material formation. In this process, a mini-scaffold would be used as a reference for geometry.
This aim introduces two new elements absent from AIM 1:
a 3D-printed polymeric scaffold as a structural guide
multi-axis acoustic testing to explore directional movement on X and Z axes.
The scaffold would contain a porous alginate substructure with encapsulated HS nutrients, incorporated by in situ gelation — alginate poured liquid into scaffold cavities and gelified with CaCl₂. No adhesive needed; alginate is retained mechanically by scaffold geometry.
Aim 3 — Visionary Aim
The long-term vision is to produce a three-dimensional self-growing sculpture where bio-leather emerges from the combination of nutrient gradient, acoustic stimulation, and bacterial growth, with vibrational frequencies as the primary design input and minimal human intervention.
If AIM 1 proves that sound organizes bacteria spatially, and AIM 2 proves that organisms follow scaffold geometry when guided by frequency, then AIM 3 applies both findings to produce a sculpture that completes itself. Two paths are explored in parallel, depending on which AIM 1 and AIM 2 combinations proved most robust:
Path
System Components
Process
Expected Result
Path A — K. xylinus + E. coli-aeBlue + polymeric scaffold
K. xylinus + E. coli-aeBlue suspended in HS liquid medium with polymeric scaffold support
Frequency-induced movement → gradual textile formation → self-grown textile structure
Bio-leather with integrated aeBlue color pattern; structural gradient between nodal zones (flexible, translucent) and antinodal zones (rigid, blue); textile grows around and through the scaffold using sound as the only directional design input.
Path B — Alginate + E. coli-aeBlue + B. subtilis + modular scaffold assembly
E. coli-aeBlue and B. subtilis suspended in sodium alginate; sequential culture at different frequencies to prevent bacterial antagonism
Modular sculpture with dual patterning: blue pigmentation from E. coli-aeBlue at frequency X and morphological texture from B. subtilis at frequency Y. Each scaffold module defines a confined growth region and is assembled post-drying into a larger structure.
Aim2 and Aim3 - Self grow scultpure
BACKGROUND
Background and Literature Context
Two peer-reviewed research citations relevant to this research
Hong et al. (2020) — Surface waves control bacterial attachment and formation of biofilms in thin layers. Science Advances, PMC7385439.
This study demonstrated that Faraday waves generated by vertical vibration of thin fluid layers (≤2mm) directly control where E. coli biofilms form on solid substrates. At stable wave amplitudes (2–5g at 120 Hz), biofilm thickness correlated spatially with wave antinodal positions — active bacteria overcame nodal hydrodynamic flows to colonize antinodes, while inactive bacteria settled passively at nodes.
The pattern was scalable: changing frequency or amplitude changed the spatial period of the biofilm. This establishes that sound-generated fluid dynamics can organize living bacterial communities into reproducible geometric patterns, providing the core physical mechanism underlying this project’s experimental hypothesis.
Aim2 and Aim3 - Self grow scultpure
Zhang et al. (2025) — Acoustofluidics Powered Synthesis of Bacterial Cellulose. ACS Sustainable Chemistry & Engineering, PMC12673587.
This study applied surface acoustic wave (SAW) stimulation directly to K. xylinus cultures and documented a 14–73% increase in bacterial cellulose pellicle production compared to static controls, with the largest gains at 96–120h of culture. The mechanism: acoustic streaming improves oxygen diffusion and nutrient distribution in the static culture environment — addressing the primary bottleneck of static fermentation, which is oxygen restriction as the cellulose film thickens. SAW-treated films also showed modified nanofiber width and increased surface roughness, indicating that acoustic stimulation affects not only the quantity but the structural architecture of the cellulose produced.
This is the first published evidence that acoustic stimulation directly enhances K. xylinus cellulose biosynthesis and alters material properties, directly supporting AIM 1b and AIM 2 of this project.
