Reversible aggregation and de-aggregation of the chemical robots themselves can lead to forming of larger clusters or chains, thus altering their hydrodynamic drag and therefore the rate at which they will sediment and be carried by a flow field. Such property to switch from single-cellular state to multi-cellular enables them e.g. to move on longer distances or to be protected against the uptake by macrophages in blood vessel. The aggregation of the artificial cells can be based on several mechanisms, such as by changing hydrophobicity, by salting or by using oligonucleotides.
- Sarvašová N., Ulbrich P., Tokárová V., Zadražil A., Štěpánek F., “Artificial swarming: towards radiofrequency control of reversible micro-particle aggregation and deposition”, Powder Technol. 278, 17-25 (2015)