DOI: 10.25835/khimutfn
title: Deformation Sensor Measurements

description: 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°.