Revolutionizing 3D cell culture with simplified digital microfluidic technology

Most cells in the human body exist in complex three-dimensional environments, yet they are still commonly studied on flat plastic dishes. These two-dimensional cultures distort cell behavior, limiting their relevance for predicting biological responses in real tissues. Microfluidic technologies have improved control over cell culture conditions, but many systems rely on continuous fluid flow, external pumps, and complicated fabrication processes. Digital microfluidics offers precise droplet-level manipulation but has struggled to support true 3D cell growth due to the absence of on-chip microstructures. Based on these challenges, there is a clear need for simpler, integrated platforms that combine precise control with physiologically relevant 3D cell culture.

In a study published (DOI: 10.1038/s41378-025-01098-9) in Microsystems & Nanoengineering in 2025, researchers from the University of Macau and collaborators describe an integrated digital microfluidic platform designed specifically for 3D cell culture. The team used a one-step micro-nano 3D printing process to fabricate three-dimensional microstructures directly onto microfluidic electrodes. The resulting chip enables controlled droplet movement, efficient cell capture, and rapid formation of 3D cell spheroids. Experiments showed stable operation and high cell viability for up to 72 hours, demonstrating the platform's practicality for advanced biological studies.

At the heart of the platform is a manufacturing strategy that merges digital microfluidics and 3D microstructures into a single device. Instead of relying on multi-step lithography and cleanroom fabrication, the researchers used projection stereolithography to print the dielectric layer, confinement fences, and micro-well arrays in one step. This approach dramatically simplifies chip production while allowing precise control over the 3D cellular microenvironment.

The team optimized key parameters that govern droplet actuation, including voltage, electrode geometry, and microstructure height. The chip reliably supported essential digital microfluidic operations such as droplet transport, splitting, and merging across both flat and 3D surfaces. Importantly, cell suspensions could be guided into the micro-wells with high precision.

Once confined within the 3D microstructures, cells rapidly self-assembled into compact spheroids. Compared with conventional two-dimensional cultures, these spheroids showed enhanced cell-cell interactions and more tissue-like organization. Viability and proliferation assays confirmed that cells remained healthy over 24, 48, and 72 hours. Imaging analyses further revealed dense multicellular architectures that closely resemble in vivo tissue structures, underscoring the biological relevance of the platform.

The researchers note that integrating 3D microstructures directly into a digital microfluidic chip addresses a long-standing bottleneck in microfluidic cell culture. They emphasize that the platform combines precise droplet control with a biologically relevant 3D environment, while avoiding complex fabrication workflows. According to the team, this balance between simplicity and functionality could help bring advanced 3D cell culture tools into broader use, particularly in laboratories that lack access to specialized microfabrication facilities.

The new platform has immediate implications for areas where realistic cell models are essential. In drug screening, 3D cell spheroids often provide more accurate predictions of drug efficacy and toxicity than flat cultures. The chip may also support research in cancer biology, tissue engineering, and organ-on-chip development by enabling controlled formation of multicellular structures. Looking ahead, the researchers plan to further reduce operating voltages and integrate sensing and multi-cell co-culture capabilities. Such advances could allow longer-term culture and more complex tissue models, narrowing the gap between laboratory experiments and living systems.