Electroporation is a powerful alternative to heat shock for delivering small molecules such as plasmids across cell membranes. By application of an electrical field netivetly charged DNA is forced into elector-competent cells by an electrohoresis-type effect. Electroporators can be expensive, generally over $2000, hence the popularity of more chemical solutions such as heat shock.
Enter the ElectroPen from the Bhamla Lab at Georgia Tech. Which can be very effectively advertised in one chart:
A paper on the electroPen is up on the bioRxiv, written by
Bhamla Lab put up all this information in one massive twitter thread, and you can read through the whole thing in a slightly more reasonable format on threadreaderapp.