Design of a treatment chamber for low-voltage pulsed electric field sterilization

- A micro-pulsed electric field under low voltage is used to improve functionality of sterilization of blueberry juice.
- Three generations bactericidal microchips under low voltage are designed and manufactured.
- Corresponding experimental platforms are established and the sterilization experiments are also carried out.
- The effects of topological parameters of the bactericidal microchips on the sterilization efficiency are clarified.
- The optimal bactericidal microchip are designed and manufactured with the aim to obtain the optimal sterilization effect.

In this paper, different microchips were simulated by the finite element method (FEM) with the aim to clarify the effect of topological parameter on inactivating microorganisms vaccinated in blueberry juice under low voltage for 50-250 μs and 20-100 pulses. For the planar comb teeth microchips in the first generation, only a 1.01 log10 of Escherichia coli (E. coli) was achieved at 25 °C in all the solutions, then, with the aim to obtain a more uniform electric field distribution, an interdigitated electrode structure are used in the second-generation microchip which improved the inactivation effect of E. coli up to 2.85 log10 reduction. At the end, by considering the problems presented by the two aforementioned microchips, the structure of a parallel plate as the third-generation microchip was designed and the best experimental platform was built. This microtreatment chamber exhibited excellent inactivation effect on E. coli, Saccharomyces cerevisiae, and Staphylococcus aureus of 5.32, 5.42, and 4.77 log10 cycles respectively. These results will provide a meaningful guidance in inactivate microorganisms by low-voltage PEF.