Seeing the Unseen Across Ten Orders of Magnitude

Backlit black-and-white profiles of an airplane wing (10 m) and a fairyfly wasp wing (0.15 mm), with scale bars, illustrating the macro-to-nano measurement range enabled by Moiré-Holography and Holographic-Moiré.

In Italian there is a wisdom saying, “Solo i Sogni Ti Fanno Volare” or “Only dreams make you fly.” The wings in our header image, one spanning 10 m, the other just 0.15 mm, stand for more than dreams: they embody NanoFraction’s ability to see, measure, and optimize across scales that once seemed worlds apart.

What if the same measurement technology that maps the flex in a 30-ton airliner wing could also chart the nanometer-scale irregularities of a virus-templated nanorod? That’s the promise of NanoFraction’s moiré-holography and its cousin holographic-moiré: two optical hybrids that, together, deliver full-field displacement maps from meters down to nanometers.

Moiré-Holography vs. Holographic-Moiré: A Tale of Two Reference Frames

Although often conflated, the terms describe distinct methods born in recent decades. The two terms describe procedures using moiré metrology, both developed by Cesar Sciammarella’s pioneering work in Experimental Mechanics. Dr. Sciammarella and his collaborator Dr. Lamberti are both scientific advisors to NanoFraction.

• Moiré-Holography, coined by Sciammarella in 1970, substitutes moiré carriers in place of holographic fringes as carriers of information. Takes the different approaches of Continuum Mechanics kinematics to solve problems of shape and deformation of media utilizing local systems of reference.

• Holographic-Moiré, fully defined by Sciammarella in 1982, adds an important component to the moiré metrology. It utilizes a global system of reference that provides the total displacements of specimens, including rigid body motions.

Choosing between them is like picking the right lens: use global moiré-holography when you need to know how an entire aircraft wing moves under load; switch to local holographic-moiré for pinpointing micro-cracks or localized deformations.

Scaling from Composite Panels to Nano-Electrodes

Macro-Scale Composites
In aerospace, NanoFraction engineers used global moiré-holography to inspect 1.5 m × 0.7m composite Boeing wing panels under bending, detecting stress concentrations, delaminations, and buckling in real time. For stiffened fuselage sections, this meant full-field deformation maps in hangars — no physical probes required.

TMV-Templated Microbattery Electrodes
At the opposite end, Tobacco Mosaic Virus (TMV) has become a nanoscale scaffold for high-surface-area battery electrodes. Spectacular work from a University of Maryland team genetically anchors TMV rods upright on a current collector, coats them with nickel or silicon, and ends up with a Li-ion microbattery anode boasting 10× the capacity of flat films(Ghodssi et al.). Here, global moiré-holography would be able to verify the virus forest’s 3D alignment on the collector (micron accuracy), while local holographic-moiré would quantify nanometer-scale coating uniformity — critical for reproducible electrochemistry.

Amy Blum’s team at McGill University has pioneered the use of Tobacco Mosaic Virus to coat-protein disks as ring-shaped scaffolds for the self-assembly of gold nanoparticles, yielding uniform plasmonic nanorings with tunable optical resonances. Each ~20 nm nanoring powers molecular-scale sensing. Local holographic-moiré would perform quality control for sub-10 nm gaps between particles, ensuring the resonant “hot spots” that amplify optical signals.

Electrospun Nanofiber Scaffolds
On the biomedical front, portable spray-on nanofiber dressings (e.g., Nanomedic’s SpinCare) are revolutionizing wound care. By projecting soft fringe patterns onto the growing fiber mat, Global moiré-holography tracks overall thickness and uniformity. Local holographic-moiré then provides feedback to fine-tune voltage and flow, producing second-skin bandages with controlled porosity for optimal healing.

The Scalability Advantage

At the heart of both global moiré-holography and local holographic-moiré lies interference of periodic patterns — a scale-agnostic principle. If two gratings differ by a tiny amount, their beat frequency (the moiré fringe spacing) can be tuned to any desired sensitivity or range. This geometric amplification works from a chipped aircraft wing to a virus’s helical protein coat. Digital enhancements — phase shifting, real-time reconstruction, AI-driven fringe analysis — only expand the dynamic range further, enabling live inspection from meters to nanometers, in labs and on the factory floor alike.

Why This Matters Now

We stand at a convergence of Industry 4.0 and bio-nanotechnology, where self-assembling biological templates meet automated, non-contact metrology. Whether you’re an aerospace engineer, a battery researcher, or a biomedical innovator, mastering these two hybrids unlocks a singular toolkit:

• Global Moiré-Holography: Global alignment, absolute motion, large-scale analysis of structural faults.

• Local Holographic-Moiré: Local precision, strain‐mapping, nanoscale quality control.

Call for Collaborators

We’re on the lookout for partners to push these techniques into real-world impact. If you’re developing next-gen wound-healing scaffolds, advanced battery architectures, or high-performance composites, let’s team up. In particular, the fight against chronic and acute wounds can benefit immediately from closed-loop control of nanofiber dressings — improving patient outcomes and reducing healthcare costs. Reach out to explore joint projects, share expertise, and co-author the next chapter of macro-to-nano metrology. Together, we’ll scale the invisible.

[1] Sciammarella, C.A., Di Chirico, G. and Chang, T.Y. Moiré-Holographic Techniques for Three-dimensional Stress Analysis, Journal of Applied Mechanics, 3 (1970)

[2] Sciammarella, C.A., Gilbert, J.A. A holographic-moiré technique to obtain separate patterns for components of displacement. Experimental Mechanics, 16, 215–220 (1976).

[3] Sciammarella, C.A. Holographic Moiré, An optical tool for the determination of displacements, strains, contours, and slopes of surfaces. Optical Engineering, 21(3), 447-457 (1982).

[4] Sciammarella, C.A., Sciammarella, F. Experimental Mechanics of Solids. Wiley: Chichester (UK), 2012.

[5] Sciammarella, C.A., Lamberti, L., Sciammarella, E., Sciammarella, F.M., Santoro, L. Digital Holographic Moiré Generalized NanoFraction. Experimental Mechanics (2025) IN PRESS.

[6] Sciammarella, C.A., Lamberti, L., Boccaccio, A. General model for moiré contouring, part 1: theory. Optical Engineering, 47(3), 033605 (March 2008).

[7] Sciammarella, C.A., Lamberti, L., Boccaccio, A., Cosola, E., Posa, D. General model for moiré contouring, part 2: applications. Optical Engineering, 47(3), 033606 (March 2008).