The study develops a water-soluble photoresist for sacrificial supports in two-photon lithography. Measured printing, dissolution, mechanical and optical tests show that supports can be removed in mild aqueous media while permanent structures remain; demonstrations include 100 µm single-clamped cantilevers and biconvex microlenses. Most tested microscale structures dissolved within 10 minutes in static room-temperature water, and flowing or 45 °C water accelerated removal to within 4 minutes. Molecular dynamics simulations support strong polymer–water affinity. Processing depends on dry condit

A LITTLE SUPPORT. A NEW FREEDOM.

At the microscale, making a shape is only half the challenge. This paper introduces a temporary, laser-printed scaffold that holds a delicate structure in place—then disappears in water.

Two-photon lithography · Water-soluble photoresist

What if the hardest part to print could borrow a foundation?

01 / A VIRTUAL FABRICATION LAB

Give the free end a foundation.

Start with a supported structure. Add water. Then try building it yourself.

A temporary scaffold holds the cantilevers in place.

Amber will dissolve. Teal will remain.

Within 10 min Reported removal for tested microstructures

Drag the model to look around. Conceptual animation of the reported sequence; dissolution and deformation are illustrative. Experimental times refer to tested microstructures. See the experiments ↗

02 / HOW IT WORKS

A scaffold with an exit strategy.

Two materials. Two printing steps. One selective rinse.

Print what you’ll remove.

A tightly focused femtosecond laser writes a 3D scaffold into a new water-soluble photoresist. Polymerization occurs in the small focal volume through two-photon absorption.

Give the final shape a foundation.

After a brief rinse, a second print places the permanent IP-S structure on the scaffold. The substrate stays fixed for alignment, allowing the two materials to meet precisely.

Let water do the release.

Water dissolves the hydrophilic scaffold while the permanent material remains. Supported cantilevers and the curved underside of a lens become free-standing features.

WHY WATER?

Strong affinity. Gentle removal.

The resin combines hydrophilic components—DAC, NVP, NIPAAM and PAAc. Water forms hydrogen bonds with the printed polymer, enabling physical dissolution. The scaffold keeps its geometry in dry conditions below 30% relative humidity.

03 / A SMALL PRINTING EXPERIMENT

Find the print window.

Too little laser power, and the scaffold never fully forms. Too much, and printing damages it. Explore the measured window at one fixed scanning speed.

SCAN SPEED 80 mm/s

Inside the print window. The paper uses 35 mW at 80 mm/s as its standard setting.

Measured thresholds at 80 mm/s; scaffold appearance is illustrative. Fig. 2 ↗

04 / WHAT BECOMES POSSIBLE

Freedom beneath the surface.

THE FREE END

A cantilever that stays intact.

A single-clamped cantilever collapsed or distorted when printed without a scaffold. With the temporary support, its form remained after dissolution.

THE HIDDEN CURVE

A lens curved on both sides.

The scaffold makes room for a biconvex microlens’s lower surface. Comparisons between measured upper and separately accessible lower profiles differed by less than 0.83 µm. The finished lens also imaged the University of Arizona and Wyant College logos.

THE POSSIBILITY

Design beyond a flat foundation.

Temporary foundations expand what two-photon lithography can build. The approach opens possibilities for micro-optics and photonics, with potential extensions to soft microrobotics and bio-integrated systems.

05 / FROM THE PAPER’S SUPPLEMENTS

Look a little closer.

Watch the scaffold disappear.

The microscopic dissolution sequence in motion.

More than one permanent resin.

Compatibility with additional permanent photoresists.

A brief rinse matters.

See the effects of insufficient and excessive washing.

Small structures. Big ideas.

Rapid Water-Soluble Sacrificial Scaffolds for Unconstrained 3D Microfabrication via Two-Photon Lithography. Zhongying Ji, Zheng Zhang, Ruilin You, N. P. Ravindu Nanayakkara, Yihan Wang, Jiabin Chen, Yuanyuan Sun, Bofan Song, Zhihan Hong, Douglas A. Loy and Rongguang Liang. Advanced Materials 38, e74112 (2026). doi:10.1002/adma.74112.

Source paper and supplements: © 2026 Wiley-VCH GmbH. Process illustrations redrawn from the reported fabrication sequence (Fig. 5); geometry and scale simplified. Graphical abstract: AI-generated conceptual illustration. Interactive models show the fabrication concept; they do not predict mechanical or optical performance.

A scaffold with an exit strategy

Print support → Print structure → Dissolve support

AI-generated conceptual illustration informed by Fig. 5; materials recolored and geometry simplified.