Schemes for pulsation protocols with different doses.

Schemes for pulsation protocols with different doses.</p

Comparison of ablation regions with the same pulse number subjected to HVP1, LVP1 and SHLVP-4 kV (HVP+LVP) pulsation.

A: Images of the ablated regions. B: The mean ablated regions (dark areas) depicted in A. Parameters: HVP1 (4 kV/cm, 2 μs, 80 pulses); LVP1 (0.6 kV/cm, 100 μs, 80 pulses); and SHLVP-4 kV (4 kV/cm, 2 μs, 20 pulses+0.6 kV/cm, 100 μs, 60 pulses). Data are shown as the average ± SD (**, pTable 5.</p

Schemes for SHLVPs with different sequences.

<p>Schemes for SHLVPs with different sequences.</p

For the similar dose, the mean ablated region (dark area) resulting from SHLVP is larger than that of LVP1.

<p>Note that 80 LVPs were used in the LVP1 protocol. The duration of the HVPs was adjusted to yield approximately the same dose for the SHLVP and LVP1 protocols. Therefore, the doses shown in Fig 2A, B, C and D produced in the three groups (LVP1, SHLVP-a and SHLVP-b) were the similar dose. All detailed protocol parameters are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0173181#pone.0173181.t001" target="_blank">Table 1</a>. Data are shown as the average ± SD; (*, p<0.05), (**, p<0.01), and (***, p<0.001).</p

Schemes for pulsation protocols with different LVP electric fields.

Schemes for pulsation protocols with different LVP electric fields.</p

Superior Surface-Insulated Polymers with Low Leakage Current Enabled by Tailored Coatings Deposited with Colliding Plasma Jets

Insufficient surface insulation margin is the primary challenge for a 10 kV plus high-voltage semiconductor module. Surface charge accumulation and electric field distortion are the leading causes of surface insulation failure. Power modules restrict leakage loss, so only insulation dielectrics with low surface conductivity can be used. However, low conductivity, accumulated charge dissipation, and distorted electric field optimization have always been contradictory. A potential barrier increase and electron affinity decrease are both less coupled approaches with conductivity, which may have the potential for reducing surface charge accumulation. Here, surface charge accumulation inhibition and local electric field optimization were synchronously realized by tailored coating deposition with colliding plasma jets. This novelty approach leads to a finer interfacial modification of the triple junction and its nearby interfaces. The high-barrier and low-affinity coatings deposited by colliding plasma jets suppress charge injection (electrode–polymer interface) and promote charge dissipation (gas–polymer interface), respectively. At the same time, the small-area semiconductor deposited at the triple junction relieves the distortion of the electric field. In the end, while maintaining a low leakage current, the surface flashover voltages of polytetrafluoroethylene, polyimide, and epoxy packaging polymers are significantly increased by 69.7, 43.2, and 39.6%, respectively. Notably, the normalized leakage loss is less than 3/10,000 of the commercially available SiC module, which vastly differs from the surface insulation improvement strategy that blindly increases surface conductivity. This tailored coating modification strategy provides a new idea for dielectric research. It has reasonable practicability due to fast, cheap, and environmentally friendly colliding plasma jets

Increased electric field strength of the LVP component of SHLVPs augments the ablation area.

The parameters were as follows: LVP2: 0.4–1 kV/cm, 100 μs, 60 pulses; SHLVP-4 kV, including HVPs (4 kV/cm, 2 μs, 20 pulses) and LVPs (0.4–1 kV/cm, 100 μs, 60 pulses). Data are shown as the average ± SD; (***, pTable 4.</p

Real-time temperature changes at points 1 and 2 as a function of the number of pulsations in LVP1 and SHLVP-4 kV.

LVP1: 1 kV/cm, 100 μs, 80 pulses; SHLVP-4 kV: HVPs (4 kV/cm, 2 μs, 20 pulses)+LVPs (1 kV/cm, 100 μs, 80 pulses). Note that the inclusion of 80 error data points in the figure would make it difficult to differentiate different protocols. Therefore, partial error data are provided in Fig 9. Data are shown as the average ± SD.</p

Schemes for pulsation protocols with the same pulse number.

<p>Schemes for pulsation protocols with the same pulse number.</p

Irreversible electroporation ablation area enhanced by synergistic high- and low-voltage pulses - Fig 10

<p>A: Model of a spherical electroporated cell exposed to an external electric field <i>E</i>. B: Model of potato tissue exposed to an external electric field <i>E</i>; the red section represents the electroporated area, where <i>E</i>><i>E</i>_<i>c</i> when HVPs are applied.</p