Embedded printing of soft materials relies on yield-stress support matrices to prevent sagging and enable freeform fabrication. The rheological parameters of the matrix material directly influence critical printing outcomes such as strand positioning, cavity formation, structural stability, and defect suppression in embedded printing. Despite widespread use of Carbopol^® formulations, a systematic rheological characterization of ETD2020 across relevant polymer concentrations and pH levels for embedded printing is lacking. Here, we implement a full-factorial design with polymer concentrations from $0.1\mathrm{wt}\%$ to $0.9\mathrm{wt}\%$ and triethanolamine dosages of 30–$50$µL per $100\mathrm{g}$. Steady-shear ($0.001$–$200{\mathrm{s}}^{-1}$) and oscillatory ($1\mathrm{Hz}$) rheometry yielded Herschel–Bulkley parameters ${\tau }_y$, k, n as well as storage and loss modulus $G^{\prime }$/$G^{\prime \prime }$. All formulations exhibited pronounced shear-thinning, with ${\tau }_y$ increasing nonlinearly from <$1\mathrm{Pa}$ to $41.1\mathrm{Pa}$ and $G^{\prime }$ reaching $\approx 400\mathrm{Pa}$ at $0.9\mathrm{wt}\%$. A five-hour window of invariant rheology was identified, followed by a $\Delta {\tau }_y\approx 10\mathrm{Pa}$ increase after five days, indicating delayed polymerization. The comprehensive material characterization defines a rheological window for ETD2020 and facilitates simulation-based modeling and the targeted tuning of matrix properties. Heatmaps provide an interpolated depiction of combined carbomer and triethanolamine concentrations, enabling tunable support matrices for embedded printing.

We present an optical deformation sensor additively manufactured via an embedded printing process that enables the direct integration of colloidal quantum dots into multimode silicone (PDMS) waveguides. The sensor consists of two parallel waveguide strands, one of which is locally functionalized with CdSe/CdS quantum dots serving as fluorescent emitters. When narrow-band UV light at 405 nm is coupled into the non-functionalized strand, structural deformation alters the conditions of total internal reflection, thereby changing the optical interaction between both strands. This leads to a deformation-dependent variation in the fluorescence shift-affected intensity ratio, which serves as a self-referenced signal for angle determination. Using ratiometric evaluation, angular deflections of up to 9.5° are detected with a resolution below 1° ($2\sigma$ confidence), representing the performance of an initial functional prototype. The embedded printing process allows the voxel-wise adjustment of the material composition within a viscoplastic support medium and thus the spatially resolved integration of quantum dot-functionalized silicone. Attenuation losses of $0.81\pm 0.02\mathrm{dB}/\mathrm{cm}$ at 625 nm confirm the optical suitability of the printed waveguides. This approach combines optical sensing and structural flexibility within a single manufacturing step and establishes a pathway toward fully integratable deformation-sensing elements for soft robotic and wearable systems.