  We present here a novel cantilever based apparatus to perform translational
stress or strain controlled rheology in very soft solids, and obtain
simultaneous confocal imaging of the 3 dimensional microstructure. The stress
is measured using eddy based sensors. Both the stress and strain are controlled
by applying PID control loops on measured quantities and changing position
using a micromanipulator. To get rid of surface tension forces, the sample and
cantilever are immersed. This enables stress measurement and control down to
3mPa. With this apparatus, we can independently apply shear and normal stress,
or strain, with same precision. We demonstrate the technical capability of the
setup with steady shear strain or stress experiments on a soft protein gel
system. The simultaneous confocal imaging offers insight into the macroscopic
breaking observed in an increasing shear strain experiment.
