Two electrospun mats made from the same solution can behave very differently depending on how the fibers were collected. The collector decides whether fibers land in a random web or line up in a preferred direction — and that orientation affects mechanical strength, porosity and how cells or fluids interact with the material.
Random mats: the flat-plate collector
A stationary grounded plate, often covered with aluminium foil or a nonwoven support, is the simplest collector. Because the jet whips chaotically before landing, fibers deposit in all directions and form an isotropic nonwoven mat.
- Strengths: simple, reproducible and well suited to parameter studies.
- Typical uses: filtration layers, membranes, wound dressings and general material screening.
Aligned fibers: rotating and gap collectors
Rotating drum or mandrel
When the collector surface moves fast enough, it pulls fibers into alignment along the direction of rotation. At low speeds the mat stays largely random; as surface speed increases, alignment improves. Very high speeds can stretch or break fibers, so speed is a parameter to optimise, not maximise. Thin mandrels are also used to make tubular structures.
Parallel electrodes (gap collector)
Two grounded electrodes separated by an air gap cause fibers to stretch across the gap, producing highly aligned fibers over a small area. This is useful for studying single-fiber properties or making small aligned samples.
| Collector | Orientation | Sample size |
|---|---|---|
| Flat plate | Random | Large, uniform mats |
| Rotating drum | Aligned (speed-dependent) | Large sheets |
| Rotating mandrel | Aligned / tubular | Tubes |
| Parallel electrodes | Highly aligned | Small areas |
How orientation changes properties
- Mechanics: aligned mats are typically much stronger and stiffer along the fiber direction than across it.
- Cell behavior: in tissue engineering research, aligned fibers can guide cells to elongate along the fiber axis — relevant for nerve, muscle and tendon studies.
- Transport: orientation influences pore shape and can affect how liquids wick through the mat.
Quantify orientation from SEM images — for example with a fiber angle distribution — and report drum surface speed rather than only revolutions per minute, since the same rpm gives different speeds on drums of different diameters.
SpinTech SE supports both flat-plate and rotating-drum collection, so you can compare random and aligned structures with the same setup.
