Figure 2
From: Color-switching hydrogels as integrated microfluidic pressure sensors
Schematic of the channel design (a) top view and (b) picture of the experimental realization, showing the orange color of the gel. The chip used is the one calibrated in Fig. 1g and Supplementay Fig. S2c. Response of the pressure sensors (c) under steady water flow at 50 \(\upmu \hbox {L}/\hbox {min}\) (blue squares). Inset: top view of the sensors at a steady flow of 50 \(\upmu \hbox {L}/\hbox {min}\). (d) Under imposed pressure difference \(\Delta P\) (bottom to top: 50 mbar, 100 mbar, 150 mbar). The response is measured from the 4 mm diameter sensors except for one data point (indicated in the figure) which is from a 1 mm diameter sensor. The pressure response as a function of distance is linear in all cases (\(R^2\) values bottom to top: 0.86, 0.98, 0.98). Error bars are often smaller than the symbol size and thus not visible on the figure. The error corresponds to the standard deviation.
