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C. Neinhuis, identified as Christoph Neinhuis in the Bonn team's 1998 nomination profile, investigated how plant surfaces repel water and shed contamination with W. Barthlott. Their work connected plant structure with biomimetics.^[ref]

The 1997 experiment compared smooth and rough water-repellent plant surfaces. After artificial contamination, the specimens were rinsed using a sprinkler or fog generator; rolling droplets removed particles from the water-repellent leaves. This supplied a functional test of the lotus effect, beyond simply imaging an unusual surface.^[ref]

An original quantitative comparison would count retained particles over equal sampled areas. Suppose two surfaces each begin with 1000 particles; after matched rinsing one retains 50 and the other 400. The respective removal fractions are $1-50/1000=95\%$ and $1-400/1000=60\%$. These hypothetical counts illustrate a measurable cleaning outcome, not data from Neinhuis's paper.

The comparison needs controls for particle type, initial loading, water delivery and how the sampled area is selected. A surface can have a large static contact angle yet pin droplets through contact-angle hysteresis. Measuring water repellency, droplet motion and contamination removal separately therefore tests more of the proposed mechanism than a single photograph of a rounded droplet.

David H. Kohn is a biomedical engineer whose research connects biomineralization, biomaterials and biomechanics. His University of Michigan profile describes two related questions: how the organization of mineralized tissue produces its mechanical behavior, and how understanding natural material formation can inform engineered biomaterials. This is an example of biomimetics: learning design principles from biological structures rather than merely copying their chemical ingredients.^[ref]

His joint work with M. D. Morris, W. F. Finney and Rupak M. Rajachar used Raman spectroscopy to investigate bone during elastic deformation. Their custom mechanical tester fitted the stage of a Raman microprobe and accepted hydrated specimens. The experiment paired loading of murine femora in tension with measurements of mineral phosphate-band shifts, while keeping loading below yield.^[ref] The combination asks how a local molecular response accompanies the deformation of an entire composite material.

An original idealized calculation explains why the two measurements are complementary. For a harmonic oscillator with effective bond force constant $k$ and reduced mass $\mu$, the vibrational wavenumber iswhere $c$ is the speed of light. Holding $\mu$ fixed gives the first-order relation $\Delta \tilde{\nu }/\tilde{\nu }\simeq \frac{1}{2}\Delta k/k$. A hypothetical band moving from $1000$ to $998\mathrm{c}{\mathrm{m}}^{-1}$ would correspond to approximately a $0.4\%$ decrease in this model's effective bond force constant. This Raman shift as a probe of bond stiffness is a local vibration model; the chosen numbers are not measurements from Kohn's paper.

A specimen's Young's modulus instead relates its macroscopic stress to its strain in a specified loading direction and regime. It cannot be read directly from one vibrational wavenumber. Composite material geometry, phase interactions and orientation mediate the connection between a local bond force constant and a bulk elastic modulus. Even a large local spectral response need not imply an equally large change in bulk stiffness.

This distinction gives the experiment its interest: a tensile testing apparatus and a spectroscopic probe observe different levels of the same loaded material. Their agreement or disagreement can discriminate structural explanations that a single bulk measurement would leave unresolved. Repeating both measurements during unloading would additionally test whether the changes reverse. Kohn's institutional description places this multiscale mechanics question alongside the development of new biomaterials.^[ref]

The Lotus effect is self-cleaning by water droplets on a strongly water-repellent, textured surface, exemplified by lotus leaves. The surface structure reduces the contact of both water and contaminating particles with the solid. Mobile droplets can collect the particles and carry them away, connecting wetting, particle adhesion and surface microstructure.^[ref]

The motivating experiment was more specific than simply noticing that leaves look clean. W. Barthlott and C. Neinhuis artificially contaminated smooth and rough water-repellent plant surfaces with particles, then rinsed them with a sprinkler or fog generator. Rolling droplets removed the particles from the water-repellent surfaces. Comparing surface types linked cleaning performance to the combination of roughness and water repellency.^[ref]

A Cassie–Baxter state provides an idealized picture of a droplet supported partly by solid asperities and partly over trapped air. This reduces the effective solid contact area. Real cleaning additionally requires the drop to move: contact-line pinning and contact-angle hysteresis can hold a droplet even when its static contact angle is large. Thus measuring a contact angle and observing particle removal are different tests.

A force estimate explains why a cleaning experiment should specify drop size and tilt. On a surface inclined by $\alpha$, a droplet of mass $m$ has a downslope component of gravitational weightFor a $10\mu \mathrm{L}$ water drop, taking density $1000\mathrm{kg}{\mathrm{m}}^{-3}$ gives $m=10^{-5}\mathrm{kg}$. At $\alpha =10^{\circ }$, the driving force is about $17\mu \mathrm{N}$. A surface that requires more force to overcome contact-line pinning can retain that drop. This is an illustrative force balance, not a measured lotus-leaf threshold; different drop volumes supply different driving forces.

For a biomimetics experiment, compare contaminated surfaces under the same droplet volume, inclination and rinsing protocol, and record both droplet motion and particles remaining. Wear or a change in surface chemistry can alter the result even if the surface still looks rough. The useful mechanism is the coupled behavior of surface texture, wetting, adhesion and droplet motion.