3D Printing of Hierarchical Structures Made of Inorganic Silicon-Rich Glass Featuring Self-Forming Nanogratings.

Hierarchical structures are abundant in nature, such as in the superhydrophobic surfaces of lotus leaves and the structural coloration of butterfly wings. They consist of ordered features across multiple size scales, and their advantageous properties have attracted enormous interest in wide-ranging fields including energy storage, nanofluidics, and nanophotonics. Femtosecond lasers, which are capable of inducing various material modifications, have shown promise for manufacturing tailored hierarchical structures.

Micro 3D printing of a functional MEMS accelerometer.

Microelectromechanical system (MEMS) devices, such as accelerometers, are widely used across industries, including the automotive, consumer electronics, and medical industries. MEMS are efficiently produced at very high volumes using large-scale semiconductor manufacturing techniques. However, these techniques are not viable for the cost-efficient manufacturing of specialized MEMS devices at low- and medium-scale volumes.

Photocycloadditions in disparate chemical environments.

We elucidate the wavelength dependence of a photocycloaddition by (i) accessing action plots dependent on the reactivity relative to the number of absorbed photons, (ii) establishing the effect on substrate concentration on photochemical reactivity and (iii) determining wavelength-dependent reactivity as a function of the solvent environment, comparing acetonitrile with dimethyl sulfoxide.

Fully independent photochemical reactivity in one molecule.

We introduce a chemically λ-orthogonal bichromophore triggered simply by different colours of light, enabling two different photochemical reactions in one molecule. Uniquely, the short wavelength (λ = 314 nm) does not trigger the red-shifted reaction system (λ = 416 nm), opening possibilities for the light controlled gating of specific molecular sites independent of wavelength.

Access to Disparate Soft Matter Materials by Curing with Two Colors of Light.

A platform technology for multimaterial photoresists that can be orthogonally cured by disparate colors of light is introduced. The resist's photochemistry is designed such that one wavelength selectively activates the crosslinking of one set of macromolecules, while a different wavelength initiates network formation of a different set of chains. Each wavelength is thus highly selective towards a specific photoligation reaction within the resist.

Photochemistry in Confined Environments for Single-Chain Nanoparticle Design.

Emulating nature's protein paradigm, single-chain nanoparticles (SCNP) are an emerging class of nanomaterials. Synthetic access to SCNPs is limited by ultralow concentrations, demanding reaction conditions, and complex isolation procedures after single-chain collapse. Herein, we exploit the visible light photodimerization of styrylpyrene units as chain folding mechanism.

Wavelength-Gated Dynamic Covalent Chemistry.

Chemical reactions are classically controlled by the judicious choice of functional groups as well as external factors such as temperature and catalysts. However, the use of light-induced reactions not only offers precise temporal and spatial control, but critically allows highly specific reaction channels to be selectively addressed through wavelength and intensity, thereby enabling targeted covalent bonds to be made and broken. Photoreversible cycloadditions are the most promising candidates to seize the outlined potential upon selective cyclization and cycloreversion, but are today still far from fulfilling these expectations.