Deformation Sensor Measurements

The datasets contain all measurement data obtained during the characterization of optical deformation sensors produced by embedded printing. Each sensor consists of two parallel silicone waveguides made from the two-component material DOWSIL EI-1184. One of the waveguides was functionalized with colloidally dispersed CdSe/CdS quantum dots to enable deformation-dependent fluorescence response.

Printing process and parameters:
The sensors were fabricated on a Snapmaker 2.0 A350 system using an active-mixing extrusion printhead. The printing speed was 30 millimeters per second. The silicone components were mixed in a ratio of 1:1 and extruded into Copsil Add-Gel support matrix. A 1.19 millimeter inner-diameter extrusion needle produced the two parallel waveguides with an overlap of approximately 20 percent to achieve optical coupling between them.

Functionalization:
The functionalized strand contained 0.5 grams per liter CdSe/CdS quantum dots dispersed in component A of the silicone. This functionalization produced a localized emission band at 625 nanometers when excited at 405 nanometers.

Sample set:
Ten sensor samples were printed. Three sensors showing high optical clarity and continuous strand geometry were selected for detailed measurements.

Measurement setup:
A 405 nanometer light source (Thorlabs M405FP1 LED, 24.3 milliwatts) was coupled into the non-functionalized waveguide using a 400 micrometer SMA fiber with a numerical aperture of 0.5. The emission at the opposite end of the sensor was collected through a 1500 micrometer SMA fiber and spectrally analyzed using a Bentham IDR-300 PSL double monochromator. The setup enabled the detection of both excitation and fluorescence signals from the same sensor.

Bending procedure:
Each sensor was mounted in a V-groove fixture and deformed using a rotary stage with an angular precision of 0.2 degrees. Measurements were taken in angular steps of 3 degrees from 0 to 30 degrees, and for selected samples, in 0.5-degree increments from 0 to 10 degrees. After each measurement, the sensor was returned to its original position to ensure repeatability.

Measured quantities:
For each deformation angle, emission spectra were recorded and normalized to the undeformed state. The fluorescence-to-excitation intensity ratio was used as the deformation-dependent signal parameter.

Results summary:
The fluorescence-to-excitation ratio increased systematically with bending angle, allowing the detection of deformations between 0 and 15 degrees. The measurement precision achieved within this range corresponded to a resolution of 0.9 degrees at a 95 percent confidence level.

Data coverage:
The dataset includes raw and processed spectral data for each sensor and deformation angle.

2024_07_29-Sensor-response-for-positive-and-negative-bending - contains measurements over a large bending area -30° to 30° for three sensors and a reference sensor (both strands functionalized with CdSe/CdS quantum dots).

2024_07_29-Sensor-response-comparison-and-repeatability - contains repeatability experiments and comparissons between the sensors with finer resolution.

2024_07_29_Sensor-response-positive-beding-fine-resolution - contains five repetitions of measurements for one sensor with a fine resolution of 0.5°.