Droplet Volume Calculator
Calculate the volume, surface area, and droplet density for microfluidic droplets. Perfect for designing and optimizing droplet microfluidic experiments.
Parameters
Assumes spherical droplets in aqueous dispersions.
Result
| Parameter | Value |
|---|---|
| Diameter | 50.00 µm |
| Volume (pL) | 65.45 |
| Surface area | 7853.98 µm² |
| Surface-to-volume ratio | 0.1200 µm⁻¹ |
| Droplets per µL | 15M |
About Droplet Microfluidics
Droplet microfluidics is a powerful technology that creates tiny, monodisperse droplets (typically 1–100 µm in diameter) within a continuous phase. Each droplet acts as an isolated microreactor, enabling high-throughput chemical reactions, cell encapsulation, and sorting with minimal reagent consumption.
Why Droplet Size Matters
Droplet diameter directly governs the volume available for encapsulation and reaction. Smaller droplets offer higher surface-to-volume ratios, enabling faster heat and mass transfer but reducing the absolute amount of cargo per droplet. Larger droplets provide more reaction volume at the cost of slower diffusion. The choice depends on your application: single-cell encapsulation requires precise size control, while PCR amplification benefits from larger volumes.
Common Generation Methods
T-junction devicescreate droplets by colliding an aqueous stream with an immiscible oil phase, ideal for droplets 20–500 µm with good monodispersity ( coefficient of variation < 5%). Flow-focusing geometries squeeze the aqueous stream between two oil streams, producing even tighter size distributions and enabling droplets as small as 5–10 µm. Coaxial devices work well for larger droplets (100+ µm) and emulsions with low viscosity contrast.
Typical Droplet Sizes
- Single-cell encapsulation: 30–100 µm (0.01–0.5 nL). Smaller droplets maximize throughput; larger ones reduce cell sorting complexity.
- PCR and DNA amplification: 50–200 µm (0.06–4 nL). Balances thermal uniformity with droplet formation speed.
- Protein crystallization: 50–200 µm. Crystal nucleation requires sufficient volume but favors the diffusion-limited regime.
- Chemical screening: 10–50 µm (0.0005–0.06 nL). Tiny droplets maximize screening throughput and reduce reagent costs.
- Emulsion templates: 200+ µm. Large droplets are easier to retrieve and analyze post-reaction.
The Role of Surface-to-Volume Ratio
The surface-to-volume ratio determines how much interface material you have per unit volume. High ratios (small droplets) mean rapid molecular diffusion and heat transfer but also increased evaporation risk and potential for unwanted adsorption onto the droplet interface. Low ratios (large droplets) enable longer incubation times and larger-scale reactions but sacrifice diffusion speed. This trade-off is central to optimizing your microfluidic workflow.
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