Food additive manufacturing technology (also known as food 3D printing) is a rapidly emerging food processing technology in the food industry in recent years, which can achieve customized food design, personalized nutrition, diversified raw material components, and simplified supply chain (Shen, Zhang, Mujumdar, & Li, 2023; Sun, Zhou, Yan, Huang, & Lin, 2018). With the integration with different fields, food 3D printing technology has been extended to the development of plant-based meat analogues, cell culture products, medical nutritional foods, and other innovative food formulas (Feng, Zhang, Bhandari, Li, & Mujumdar, 2025). At present, food 3D printing technology can be divided into four types based on different printing methods: extrusion-based printing (Guo et al., 2022; Shen et al., 2023), inkjet printing, (Pitayachaval, Sanklong, & Thongrak, 2018), binder jetting (Sadaf, Bragaglia, Perše, & Nanni, 2024; Zhu et al., 2022), selective sintering (Sohel, Sahu, Mitchell, & Patel, 2025). Among them, the extrusion-based printing method is currently the main printing form used (Hussain, Malakar, & Arora, 2022; Preethi, 2024), which can be divided into three subtypes based on the difference in extrusion methods: screw extrusion printing (Ozdemir et al., 2024; Y. Wang et al., 2024), plunger extrusion printing (Reynolds, Rau, Williams, & Bortner, 2023; J. Wang et al., 2024), and pneumatic extrusion printing (Karyappa et al., 2024; Pan et al., 2024).

Compared to other extrusion methods, pneumatic extrusion has the advantages of simple equipment structure (Jiang, Zhang, & Mujumdar, 2022; Zhang, Noort, & van Bommel, 2022), good operability and maintainability, low cost (Preethi, 2024), and a wider viscosity range for food ink (Pan et al., 2024), making it has more scalability potential. In previous reports, our team has successfully combined pneumatic extrusion printing modules with selective compliant assembly robot arm (SCARA) systems and vision-based defect detection and automatic repair systems (Cui et al., 2025), and achieved batch 3D printing of food by installing continuous feeding modules (Lin et al., 2025) and multiple extrusion printing nozzles (Pan et al., 2024), respectively.

However, so far, most food 3D printing equipment can only achieve printing with a single food ink in a single operation. The development of multi-ink combination printing technology using multiple printing nozzles is receiving increasing attention. Chen et al. achieved co-printing of drug capsules using a multi-nozzle system (Chen et al., 2021). Sevcik et al. designed a dual-feed extrusion method and achieved dual-component color printing (Sevcik et al., 2024). Ren et al. pioneered a rotational co-extrusion combined printing method for heterogeneous filaments (Ren et al., 2023). Fujiwara et al. developed a four-screw extrusion system and conducted preliminary experiments on dual-ink hybrid printing on a delta 3D printer (Fujiwara et al., 2025). Although these reports provide reference for color high-fidelity food 3D printing (Yuan, Chen, Li, Prautzsch, & Xiao, 2021), adding food ink with additional colors requires more extrusion devices and more complex control systems, which will greatly increase production costs. Developing a multi-ink synchronous printing strategy is one of the methods to solve the above problems. Our team has proposed a two-color ink food printing method based on SCARA (Pan et al., 2025). However, achieving synchronous printing of more inks means that the pneumatic compression module of the printer must be able to allocate corresponding air pressure based on the rheological properties of different food inks.

Therefore, based on previous reports, this study integrates modular toolheads and configurable pneumatic circuits into SCARA food 3D printers on the basis of pneumatic extrusion printing, and achieves multi-ink synchronous printing and multi-mode printing by developing multi-extruder fixtures. It effectively improves the production efficiency of food 3D printing products, significantly improves the adaptability of printing equipment to materials and the diversity of product output, and verifies the scalability potential of pneumatic extrusion printing equipment.