Multi-Photon Micro- and Nano-Additive-Subtractive Hybrid Manufacturing Platform

Overall Product Overview

The multiphoton micro- and nano-scale additive–subtractive hybrid manufacturing platform is an integrated ultrafast 3D micromachining system developed by Femtika and distributed in China by Beijing Yunshang Intelligent Manufacturing Technology Co., Ltd. At its core, the platform leverages femtosecond laser technology and integrates two key processes: multiphoton polymerization (MPP) additive manufacturing and selective laser etching (SLE) subtractive manufacturing. It can also be extended to enable a wide range of micro- and nanoscale fabrication operations, including refractive-index modification of transparent materials, micro-ablation, surface structuring, and micro-welding, making it a modular, comprehensive system tailored for precision manufacturing at the micro- and nanoscale. By overcoming the limitations of conventional micromachining technologies in terms of resolution, material compatibility, and structural complexity, the platform can fabricate three-dimensional structures in polymers, fused silica, borosilicate glass, and other materials across scales from the nanometer to the millimeter. It is capable of producing mesoscale structures whose overall dimensions far exceed the scale of individual features; for example, by increasing the objective’s working distance, it can fabricate a 1 mm × 1 mm × 1 mm three-dimensional helical structure, with a height that significantly surpasses the objective’s nominal working distance of 0.19 mm.

As a laser nanomanufacturing workstation, this platform supports a wide range of sample holders, including microscope slides, wafers, and optical fibers, and can be paired with various optimized processing heads to meet diverse laser machining requirements. It not only satisfies the customized R&D needs for micro- and nanostructures in the research domain but also accommodates the high-precision, low-volume production of microcomponents in industrial applications. By providing an integrated solution for the fabrication of functional devices in fields such as microelectromechanical systems, micro-optics, microfluidics, and biomedicine, the platform enables the synergistic integration of additive and subtractive manufacturing processes in the micro- and nanomanufacturing sector, making the monolithic fabrication of complex micro- and nanostructures a reality.

Product Operating Principle

The core operating principle of the multiphoton micro- and nano-scale additive–subtractive hybrid manufacturing platform revolves around the interaction between femtosecond lasers and materials. By leveraging the synergistic operation of two fundamental processes—additive manufacturing and subtractive machining—the platform enables the fabrication of micro- and nanostructures. Both processes employ laser direct-writing technology for precise positioning and patterning, and can be seamlessly switched on the same system through parameter adjustments. Moreover, additional processing capabilities are realized by exploiting the nonlinear interactions and material-modification effects induced by laser–material interactions.

Multiphoton polymerization (MPP), as a core additive manufacturing process, is a photopolymerization technique based on direct laser writing. Its operating principle relies on the nonlinear absorption of photons: polymerization occurs exclusively at the laser focus, enabling sub-micron–scale precision fabrication. The fabrication process comprises three steps: first, a polymer material is mixed with a photoinitiator and drop-cast onto a glass slide for pre-baking, yielding a photoresist sample; second, femtosecond laser direct writing is employed, with the laser tightly focused on specific locations within the sample; upon absorbing multiple photons, the photoinitiator becomes excited, triggering photopolymerization of the polymer and causing the polymer material in the irradiated region to harden and solidify; finally, the sample is immersed in an organic solvent for development, during which the unpolymerized photoresist is removed, leaving behind the desired three-dimensional polymeric micro- and nanostructures. Throughout this process, the laser’s high degree of spatial confinement ensures that polymerization occurs only at the focal point, allowing the construction of arbitrarily complex three-dimensional geometries while enabling precise control over fabrication accuracy by tuning laser parameters.

Selective Laser Etching (SLE), as a core subtractive manufacturing process, employs a two-step approach—laser modification followed by chemical etching—specifically designed for the micro- and nano-fabrication of glass materials. In the first step, ultrashort femtosecond laser pulses are used to precisely modify the bulk properties of glass materials such as fused silica and Borofloat 33 by direct laser writing into designated internal locations, altering the chemical composition and structural characteristics of the modified regions and thereby creating a differential etching rate compared with the unmodified areas. In the second step, the laser-modified glass is immersed in a chemical etchant, where the modified regions are preferentially etched while the unmodified regions retain their original structure, ultimately yielding mechanically stable, highly precise three-dimensional glass micro- and nanostructures. This process allows direct import of CAD-designed toolpaths, enabling the accurate fabrication of internal microchannels and microcomponents within glass. Post-etching, the sidewall roughness of the etched features can be as low as 100 nm (RMS), with bottom roughness around 200–300 nm (RMS), thus ensuring exceptional structural precision.

The platform’s advanced fabrication processes are likewise enabled by the unique properties of femtosecond lasers. For instance, refractive-index modification of transparent materials is achieved by laser irradiation to alter the material’s intrinsic optical properties; micro-ablation leverages the thermal effects of lasers to enable precise material removal; and surface structuring uses laser control to create micro- and nano-scale surface textures. Each process relies on precise adjustment of laser parameters and highly accurate positioning control to deliver tailored processing outcomes.

Product Advantages and Key Features

The core advantage of the multiphoton micro- and nano-scale additive–subtractive hybrid manufacturing platform lies in its seamless integration of additive and subtractive processes, coupled with high-resolution, high adaptability, high flexibility, and high-precision machining capabilities. Moreover, the system features a modular design that allows for scalable expansion based on application requirements. Compared with conventional single-function micro- and nano-manufacturing equipment, this platform exhibits distinct advantages in processing capability, application versatility, and part-quality outcomes, as evidenced across multiple dimensions, including process technology, precision, materials, structural design, and overall equipment architecture.

In terms of process integration, the platform breaks down the hardware barriers between additive and subtractive manufacturing processes. A single system can simultaneously support multiphoton polymerization additive manufacturing and selective laser etching subtractive manufacturing, while also being extensible to a range of additional processes such as refractive-index modulation and micro-ablation. This eliminates the need to transfer samples between different machines, thereby avoiding positioning errors and structural damage during sample handling and simplifying the fabrication workflow for complex micro- and nanostructures. Moreover, additive and subtractive processes can be used in tandem—for example, first fabricating glass microfluidic channels via selective laser etching, followed by integrating polymer filters within these channels through multiphoton polymerization—enabling the monolithic integration of glass and polymer components and paving the way for the fabrication of more functionally sophisticated micro- and nano-devices.

In terms of machining accuracy and forming quality, the platform delivers nanometer-level additive manufacturing precision and micrometer-level subtractive machining precision. The multiphoton polymerization process achieves a minimum XY feature size of 150 nm and a minimum surface roughness Ra of less than 20 nm, enabling seamless, error-free precision fabrication—including ultra-fine structures such as photonic crystals with single-line widths below 200 nm. The selective laser etching process offers a minimum feature size of approximately 1–2 μm, a minimum microhole diameter of 5 μm, and an aspect ratio greater than 1:200, allowing for the fabrication of glass structures with very high length-to-diameter ratios while maintaining controllable surface roughness after processing. Moreover, the clearance between moving parts can be reduced to less than 10 μm, thereby minimizing friction and ensuring the motion stability of micro-mechanical components. In addition, the platform is capable of fabricating mesoscale structures whose overall dimensions exceed those of the fundamental features by several orders of magnitude, thus overcoming the traditional trade-off between feature scale and overall size in micro- and nano-manufacturing.

In terms of material compatibility, the platform supports a wide range of processable materials. Additive manufacturing processes can accommodate polymers such as SZ2080, SU-8, organic–inorganic hybrid photopolymers, elastomers, and proteins, as well as biodegradable polymers, thereby meeting the diverse material-property requirements across different application areas. Subtractive manufacturing, on the other hand, is primarily suited to glass materials like fused silica and Borofloat 33, which exhibit biocompatibility, chemical inertness, and optical transparency—making them ideal for fabricating microfluidic and micro-optical devices. The processing parameters for each material have been meticulously optimized, allowing users to freely select and combine materials based on device-function requirements, thus opening up a broader spectrum of design possibilities.

In terms of design and processing flexibility, the platform adopts a modular architecture that supports a wide range of sample holders, including microscope slides, wafers, and optical fibers. It can be paired with different fabrication heads to optimize performance for various laser applications, enabling the processing of samples with diverse shapes and sizes. The processing speed strikes a balance between precision and throughput: multiphoton polymerization achieves a maximum fabrication rate of 30 mm/s, while selective laser etching and writing reaches 50 mm/s, meeting the efficiency requirements of both research and small-batch production. Moreover, the multiphoton polymerization process can fabricate surfaces with varying qualities and functionalities on the same structure, tailored to specific application needs. Micro-optical components can even be directly printed onto functional elements such as fiber tips, enabling integrated device fabrication. Furthermore, processing paths can be directly imported from CAD designs, allowing for the precise replication of complex three-dimensional structures.

Furthermore, the fabrication process on the platform exhibits excellent controllability: by tuning parameters such as laser power, scanning speed, and focusing conditions, the dimensions and dimensional accuracy of the fabricated structures can be precisely controlled. Moreover, the non-contact nature of the process eliminates mechanical damage to the material that is inherent in conventional manufacturing methods, thereby ensuring the integrity and stability of the micro- and nanostructures.

Product Application Areas and Use Cases

Leveraging its capabilities in multi-process integration, high precision, and multi-material processing, the multiphoton micro- and nano-additive–subtractive manufacturing platform has been successfully applied across multiple fields, including micro-optics, micromechanics, microfluidics, biomedicine, and photonics. It enables the fabrication of a wide range of functional micro- and nanodevices and serves as a core manufacturing solution for research and development as well as production in areas such as lab-on-a-chip systems, in vitro models, and photonic devices. Several representative application cases have already achieved mature structural fabrication and functional validation.

In the field of micro-optics, it is possible to fabricate devices such as microprisms, microlenses, and photonic crystals. For example, microprisms for ellipsometers—featuring a grating on one side—can be directly printed onto the tip of an optical fiber to enable filtering and detection of optical signals. Photonic crystals can achieve feature widths below 200 nm, and their periodic structures can be used to modulate light paths, thereby meeting the fabrication requirements of photonic devices. In the realm of micro-mechanics, micro-components such as Geneva wheels, 3D mesoscopic springs, and glass screw threads can be manufactured. The Geneva wheel is integrally formed from a single piece of glass, eliminating the need for assembly, with inter-gear clearances less than 10 μm, enabling smooth intermittent rotational motion. Meanwhile, 3D mesoscopic springs exhibit excellent flexibility, making them well suited for applications in micro-robots and precision instrumentation.

In the fields of microfluidics and biomedicine, the core application is the fabrication of lab-on-a-chip devices. A typical example is the liver-on-a-chip, which employs selective laser etching to create glass microfluidic channels, followed by multiphoton polymerization to integrate polymeric filters within these channels. The resulting microfluidic device, comprising glass channels and polymeric micropillars, enables controlled cell culture and intercellular interactions, serving as an in vitro liver model for biomedical research. Another example is a microfluidic macromolecule separator, in which fused silica channels are fabricated via laser ablation, and a fine 3D filter with 500-nm pores is integrated through multiphoton polymerization. This device can separate low-molecular-weight from high-molecular-weight species in mixed solutions, thereby meeting the needs of next-generation drug development and manufacturing.

In addition, the platform can fabricate 3D glass nozzles, microfluidic channels, and other devices. The 3D glass nozzles enable precise delivery of high-pressure gases and liquids, while the microfluidic channels are made from fused quartz glass, featuring zero taper and ultra-low surface roughness—making them well suited for scientific applications such as biochemical research. In the field of photonics, the platform can produce a wide range of photonic crystals and photonic devices, leveraging periodic micro- and nanostructures to achieve precise control over light propagation, thereby providing essential support for research in nanophotonics.

3. Key Advantages and Highlights: