  Planetesimals or smaller bodies in protoplanetary disks are often considered
to form as pebble piles in current planet formation models. They are supposed
to be large but loose, weakly bound clusters of more robust dust aggregates.
This makes them easy prey for destructive processes. In microgravity
experiments, we apply strong electric fields on clusters of slightly conductive
dust aggregates. We find that this generates enough tensile stress on the
fragile clusters to sequentially rip off the aggregates from the cluster. These
experiments imply that electric fields in protoplanetary disks can dissolve
pebble pile planetesimals. This process might induce a bias for the local
planetesimal reservoir in regions with strong fields. Planetesimals prevail
with certain kinds of compositions where they are either good isolators or
compacted bodies. The less lucky ones generate pebble clouds which might be
observable as signposts of electrostatic activity in protoplanetary disks.
