  Precisely measuring pressure in microfluidic flows is essential for flow
control, fluid characterization, and monitoring, but faces specific challenges
such as \RE{achieving} sufficient resolution, non-invasiveness, or ease of use.
Here, we demonstrate a fully integrated multiplexed optofluidic pressure
sensor, entirely decoupled from the flow path, that enables local pressure
measurements along any microfluidic channel without altering its flow geometry.
The sensor itself relies on the compression of a soft mechano-actuated
hydrogel, changing color in response to a pressure change. The hydrogel is
separated from the fluid circulating in the channel by a thin membrane,
allowing for the unrestricted use of different types of fluids. Imaging the gel
through the transparent PDMS with a color camera provides a direct, easy, and
contact-free determination of the fluid pressure at the sensing location for
pressures as small as \SI{20}{\milli\bar} with a resolution of around
\SI{10}{\milli\bar}. The sensitivity and accessible pressure range can be tuned
via the mechanical properties \RE{of the sensing unit}. The photonic gel can
also be used to acquire 2D pressure or deformation maps, taking advantage of
the fast response time and fine spatial resolution.
