A New Standard of Measurement
The CROWN Diagnostic is a multi-sensor device that performs comprehensive hair strand analysis in 60 to 90 seconds. Being developed with guidance from ETH Zürich, it integrates four complementary sensing modalities — optical micro-imaging, near-infrared spectroscopy, impedance sensing, and AI-driven classification — into a single tabletop platform designed for deployment in research settings, clinical environments, and trained professional salons.
The device exists because CROWN’s research mission requires it. The CROWN Discrimination Index cannot function without hardware-verified diagnostic data to calibrate its survey instruments. The CROWN Hair Commons cannot grow without standardised, reproducible measurements captured at scale. The AI classification engine cannot achieve cross-ethnic accuracy without diverse, sensor-verified training data.
In each case, the same principle applies: objective measurement is the prerequisite for credible science, and credible science is the prerequisite for effective law.
Four Sensor Modalities
Each sensing modality in the CROWN Diagnostic captures a distinct dimension of hair properties. Their combination produces a comprehensive profile — the CROWN Hair DNA — that far exceeds what any single measurement technique can achieve.
1. Optical Micro-Imaging (200x to 400x Magnification)
What it measures: Fibre diameter at 0.1 micrometer precision. Cuticle layer condition and integrity. Cross-sectional shape (ellipticity index). Surface morphology and damage patterns.
Why it matters for research: Fibre diameter is one of the most fundamental properties of human hair, yet it is almost never measured in non-laboratory settings. The Walker classification system (1A through 4C) attempts to categorise hair by visual curl pattern alone, ignoring diameter entirely. Research published in the Journal of Investigative Dermatology (Washington State University, 2024) demonstrated that hair phenomics — the comprehensive measurement of hair properties — reveals population-level variation that simple classification systems miss.
Optical micro-imaging provides the structural foundation of the CROWN Hair DNA profile. It replaces what has historically required scanning electron microscopy in a research laboratory with a measurement that can be performed in 15 seconds in a salon chair.
What it reveals about discrimination: Cross-sectional shape and fibre diameter correlate with the textural properties — curl, coil, kink — that trigger discriminatory responses. By measuring these properties objectively, CROWN can establish whether an individual’s hair falls within the range that research identifies as subject to bias, transforming subjective claims of discrimination into measurably defined characteristics.
2. Near-Infrared Spectroscopy (900 to 1700 nm)
What it measures: Hydration levels (water content distribution within the fibre). Protein structure integrity (keratin bond quality). Lipid content (natural oils and applied products). Chemical residue signatures from relaxers, straighteners, and treatments.
Why it matters for research: Near-infrared (NIR) spectroscopy is a well-established analytical technique used across pharmaceutical, agricultural, and materials science applications. Applied to hair, it provides a non-destructive window into the molecular composition of the fibre — information that is invisible to visual inspection and inaccessible to optical imaging alone.
The spectroscopic signature of a chemically relaxed hair fibre differs measurably from that of an untreated fibre. The disulfide bonds that maintain keratin’s structural integrity are permanently disrupted by chemical straightening, producing a distinct spectral pattern in the 1100 to 1300 nm region.
What it reveals about discrimination: Chemical treatment history is direct, measurable evidence of conformity pressure. Research from the National Institutes of Health (NIH, 2022) established a statistically significant association between chemical hair straightener use and increased health risks, including uterine cancer. When an individual chemically alters their natural hair texture to conform to workplace appearance standards, that choice carries documented health consequences.
NIR spectroscopy allows CROWN to detect and quantify chemical treatment — not to judge individual choices, but to generate population-level data on how many people are chemically altering their hair, and to correlate that data with the CDI to understand the relationship between discrimination prevalence and conformity behaviour. This is the kind of evidence that transforms policy debates.
3. Impedance Sensing (100 Hz to 100 kHz)
What it measures: Moisture absorption rate (how quickly hair absorbs and releases water). Porosity index (the degree to which the cuticle permits moisture transfer). Electrical conductivity variation across the fibre.
Why it matters for research: Hair porosity — the capacity of the hair shaft to absorb and retain moisture — is one of the most practically significant properties for hair health and care. High-porosity hair (common in chemically treated or heat-damaged fibres) absorbs water rapidly but loses it equally fast, creating a cycle of dryness that affects styling, breakage, and overall hair condition.
Currently, porosity is assessed by stylists through subjective tactile evaluation or rudimentary water-float tests. Impedance sensing, which measures how electrical current flows through the hair fibre across a range of frequencies, provides a quantitative porosity measurement that is reproducible across operators and conditions.
What it reveals about discrimination: Porosity data, when aggregated across populations and linked to the CDI, helps researchers understand the physical consequences of discrimination-driven hair practices. Repeated chemical treatment and heat styling — often undertaken to conform to Eurocentric appearance norms — systematically increases porosity, creating measurable structural damage. Population-level porosity data, correlated with discrimination indices, produces evidence of the physical toll of appearance conformity.
4. AI Classification Engine
What it does: Pattern recognition across all sensor inputs. Multi-dimensional classification producing the CROWN Hair DNA profile. Anomaly detection for unusual combinations of properties. Longitudinal tracking of changes over time.
Why it matters for research: Raw sensor data from three modalities — optical, spectroscopic, and electrical — must be integrated into a coherent, interpretable profile. The AI classification engine performs this integration, trained on data from the CROWN Hair Commons to ensure equal accuracy across all ethnic hair types.
The classification challenge is substantial. Hair properties vary not only across populations but within individuals (crown versus nape, for instance), across environmental conditions (humidity, temperature), and over time (seasonal changes, product accumulation). The AI engine must produce consistent classifications despite this natural variation while remaining sensitive to genuine changes in hair condition.
From Scan to Commons
Every scan performed by a CROWN Diagnostic follows a defined data pathway:
Capture. The four sensor modalities acquire data simultaneously during a 60 to 90 second measurement session. The individual receives their CROWN Hair DNA profile — a comprehensive characterisation of their hair properties.
Anonymisation. Before any data leaves the device, personally identifiable information is stripped. The hair profile is assigned a randomised identifier. This process is compliant with the EU General Data Protection Regulation (GDPR) and Switzerland’s revised Federal Act on Data Protection (nDSG).
Contribution. The anonymised profile is transmitted to the CROWN Hair Commons, where it joins a growing dataset of sensor-verified hair measurements linked to voluntary demographic and psychosocial data.
Calibration. Commons data is used to refine the AI classification engine, improving measurement accuracy for subsequent scans. It also calibrates the CROWN Discrimination Index, linking objective hair properties to self-reported discrimination experiences.
This pipeline — from individual measurement to population-level research infrastructure — is the engineering expression of CROWN’s mission. The device does not exist in isolation. It is the data-capture layer of an integrated system that connects measurement to research to evidence to law.
Engineering as Ethics
The design of a measurement instrument embeds ethical commitments. What a device can measure determines what researchers can study, what policymakers can regulate, and what individuals can prove.
CROWN’s Diagnostic is designed to measure all hair types with equal precision. This is not a feature added after initial development; it is a foundational engineering requirement that shapes every sensor specification, every calibration protocol, and every element of the AI training methodology. The historical pattern in diagnostic tools — designing for the majority population and then attempting to extend coverage — produces instruments that systematically underperform for the people who most need accurate measurement.
CROWN reverses this pattern. Universal coverage is the architecture.
Developed with ETH Zürich
CROWN is in advanced discussions with ETH Zürich, where a professor in the Department of Biosystems Science and Engineering has expressed interest in exploring the supervision of student research projects on multi-sensor hair diagnostic systems. This developing relationship would provide CROWN with access to world-class engineering expertise while offering students a compelling, real-world multi-sensor integration challenge with direct social impact.
Current areas of active development include miniaturisation of the multi-modal sensing platform, cross-calibration protocols for ensuring measurement consistency across devices, and spectroscopic method validation for chemical treatment detection. Each of these challenges represents a potential thesis topic for engineering students seeking to apply technical skills to a meaningful research problem.
A Note on Framing
It is worth stating explicitly what the CROWN Diagnostic is not. It is not a consumer electronics product. It is not a beauty device. It is not a gadget.
It is a research instrument — developed with the same rigour and to the same standards as any other scientific measurement tool. Its value is not in the device itself but in the data it produces, the research that data enables, and the evidence that research provides to legislators, employers, educators, and courts.
The analogy is deliberate: what the Fitzpatrick scale did for dermatology, the CROWN Diagnostic and CROWN Hair DNA aim to do for the science of hair. Not a product. An infrastructure.