Near-Perfect Thermal Efficiency! Morphon's Precision Microfabrication Empowers the Creation of Novel Porous Metasurface Evaporators via 3D Printing

In the global push for efficient renewable energy utilization, steam generation technology—an essential component of energy conversion and transmission—has emerged as a pivotal breakthrough for advancing low-carbon energy systems. In recent years, researchers have systematically tackled the challenge of enhancing thermal energy efficiency, successfully developing thermodynamic optimization models that minimize heat loss and engineering adaptive evaporator systems suitable for diverse operating conditions, thereby laying a scientific foundation for technological evolution.

The innovative application of metasurface technology presents a new paradigm for advancing evaporator performance. As a functionalized surface derived from unit-cell structural designs, metasurfaces enable active modulation of properties such as surface wettability and acoustic impedance through the precise control of micro- and nanoscale pores and topologies. Among them, porous metasurfaces, with their programmable unit-cell pore structures, demonstrate exceptional capability in regulating liquid transport, thermal diffusion, and multiphase scattering phenomena. Compared to conventional engineered systems, these surfaces—fabricated via advanced additive manufacturing—can integrate microscale chemical gradients and structural heterogeneity within three-dimensional spaces, creating highly active evaporation interfaces that markedly enhance the dynamic stability of phase-change processes.

Building on this concept, a joint research team from Chiba Institute of Technology and the University of Michigan unveiled a novel design framework for 3D porous metasurface evaporators. Previously, the team employed sintered metal powders to fabricate 3D metasurface wicks with micro-capillary networks, achieving significant improvements in evaporation efficiency. In their latest work, they once again constructed 3D metasurface wicks—this time using micro/nanoscale 3D printing—achieving precise control over pore spacing tolerances. The resulting structures offer innovative solutions for solar-powered steam generation and industrial waste heat recovery. This research, titled “3D-printed, ceramic porous metasurface wick: Hexagonal-prism unit-cell capillary evaporator”, was published in the International Journal of Heat and Mass Transfer.

Drawing from prior work, the team designed an evaporator wick based on unit-cell geometry, integrating a capillary artery network atop a monolayer porous substrate to form a dual-functional system that facilitates both fluid transport and heat diffusion. Through the synergistic effects of an extended evaporation interface and continuous substrate wetting, the system remains resistant to dry-out even under high heat flux densities reaching 300 kW/m². This multiscale architecture optimally balances capillary and viscous forces, increasing the evaporation rate by up to 50%, with thermal efficiency nearing the theoretical maximum (η = 0.98).

In this study, the hexagonal-prism unit-cell evaporator core was fabricated using Morphon’s projection micro-stereolithography (PμSL) technique (microArch® S240, precision: 10 μm). The core features a thickness of 375 μm, a porosity of approximately ε ≈ 0.70, a maximum capillary pressure of about 400 Pa, and a permeability of roughly 10⁻⁹ m².

Figure 1. Schematic of the 3D-printed hexagonal-prism unit-cell evaporator core.

In earlier experiments, the team produced capillary-network-integrated cores using graphite molds and layered copper sintering techniques. However, while traditional sintering allows for structural formation, it is limited by mold constraints and material uniformity. In contrast, Morphon's micro/nano 3D printing technology—free from mold restrictions and compatible with diverse materials—can flexibly fabricate high-performance ceramic structures such as alumina and zirconia, as well as specialized polymers, thus overcoming the dual limitations of structural freedom and iterative design efficiency posed by mold-based methods.

Figure 2. (a) Optical image of a 3D-printed 10 mm × 20 mm alumina hexagonal-prism evaporator with a 1 mm base; (b) Close-up of the wick structure captured via scanning X-ray microscopy (SXM).

Preliminary experimental results demonstrated that copper-sintered capillary networks boosted evaporation rates by up to 50% and achieved near-complete thermal efficiency. The optimized design maintained high liquid–vapor interfacial area while preventing dry-out, thereby enabling stable thin-film evaporation. These performance enhancements highlight the structure's vast potential for applications in solar steam generation, adsorption-based refrigeration, and passive cooling systems.

In this study, the research team further validated the advantages of micro/nano 3D printing in the fabrication of thermal management devices. This approach enabled a breakthrough in design complexity and integration, significantly reducing development cycles compared to conventional methods. Furthermore, Morphon’s open and compatible material systems facilitate the development of advanced ceramics and metamaterials, opening new possibilities for engineering materials tailored to extreme environments.

Figure 3. (a) Representative snapshot of simulated cross-sectional temperature distribution ⟨k⟩ and electrical conductance G/dd of the hexagonal-prism evaporator core used to predict effective thermal conductivity; (b) Flow lines and velocity distribution in a rectangular domain used to estimate permeability K, applicable for pc = 375 Pa.

This research not only marks a theoretical breakthrough in evaporation science but also underscores the pivotal role of precision manufacturing in the integration of academia, industry, and research. Morphon’s micro/nano 3D printing technology—distinguished by its ultra-high resolution, multi-material compatibility, and intelligent automation—has successfully advanced thermal energy utilization from traditional macro-engineering to refined microscale manipulation, offering a compelling Chinese solution for global energy transition efforts.

As China’s “dual-carbon” goals deepen, the development of efficient thermal technologies must be guided by policy and driven by industrial collaboration. From laboratory prototypes to mass production, the rapid iteration capabilities of micro/nano 3D printing will dramatically shorten the commercialization timeline. Looking ahead, Morphon aims to continue fostering cross-disciplinary innovation and solidify China’s leading position in the global green manufacturing arena.

Original link: https://doi.org/10.1016/j.ijheatmasstransfer.2025.127041](https://doi.org/10.1016/j.ijheatmasstransfer.2025.127041