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Scientific Reports volume 14, Article number: 19001 (2024 ) Cite this article industrial uv printer
UV sensing 3D printed optical fiber hydrogels provide a flexible and precise method of remotely of detecting exposure to UV radiations. The optical fibers were created using digital light processing 3D printing technique with hydrogel composites, including micro-sized photochromic dyes (pink, blue and their combination). When exposed to ultraviolet (UV) radiation, these dyes exhibited specific absorption characteristics, resulting in significant decreases in both reflection and transmittance mode spectra at 560 nm, 620 nm, and 590 nm. Optical fibers of lengths 1, 2, and 3 cm were manufactured in two orientations: vertical and horizontal. Scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction were utilized to characterize the printed fiber probes. The optical performance of the fibers was tested using customized measurement setups. The reflection and transmission of the printed fibers reduced as the length increased due to optical losses. Reflection and transmisson loss of 20–40% can be observed when the length is increased from 1 to 3 cm. The maximum loss in reflection is observed for pink fiber in the presence of UV irradiation. Also, the type of powder used impacted the response and retraction time, whereas the mixed fiber showed the highest response time of 12–20 s under various conditions. The pink dye added fiber probes shows quick response to UV radiation. An increase in the response time is observed with increasing fiber length. The impact of printing orientation on the transmission and reflectance mode operations of optical fibers was assessed. In addition, the stability of the fiber probes are assesed using a green laser having wavelength 532 nm. This work comprehensively examines the optical properties, manufacturing procedures, and sensing capacities of UV-sensitive photochromic optical fiber sensors.
An ultraviolet (UV) sensor is a device used to measure or detect UV radiation having a wavelength (˂400 nm) higher than X-ray and lower than the visible spectrum. The primary source of UV radiation is the sun, around 10% of total radiation. Electric cars, tanning beds, and welding arcs also are great sources of UV radiation1. The long wavelength UV radiation of 350–400 nm has comparatively less energy and is not considered ionizing radiation, but it causes chemical and biological reactions2. Short wavelength UV radiation of 230–280 nm is ionizing radiation that is harmful to humans and causes skin cancer, DNA damage, sunburn, and tan3. Therefore, monitoring UV radiation is necessary to avoid skin damage and promote overall health. For this purpose, UV sensors are widely used. The conventional sensors consist of photodiode arrays that respond to UV signals by converting that into electrical pulses4. But these sensors are not suitable for harsh conditions and have a chance to create faulty readings due to magnetic and electrical disturbances5,6,7.
Optical fiber (OF) sensors are a family of sensors that can operate in harsh conditions and rule out magnetic and electrical interferences8,9. The signals from these types of sensors can transmit to longer distances without much distortion10. They work based on different principles, such as variations in light intensity, polarization, phase, and/or wavelength. The sensing part of the optical fiber can be an interferometric setup, Bragg grating, special coatings, or added impurities11. These fibers are generally made of silica, polymers, or polymer-based composites, which are crucial for operating in harsh conditions12. Optical fibers can be used as an alternative to conventional UV sensors due to their accuracy, versatility, and flexibility. They are also relatively inexpensive for UV light sensing. Feng et al.13 developed a UV sensing OF sensor using ZnO nanorods in standard single-mode optical fiber. They used a micro-nano fiber coated with a thin film of ZnO nanorods for UV detection. The photonic excitation of ZnO nanoparticles under UV exposure caused the generation of electron–hole pairs on the surface of the OF causing its refractive index to change. This change in the refractive index is used for monitoring UV radiation. Yan et al.14 used La2O2S: Eu for UV radiation detection. They fabricated polymethyl methacrylate polymer based optical fibers with scintillating nanomaterials that responds to UV radiation. These materials show high resistance to external harsh environments during sensing operation. However, there are only a few studies reported on optical fiber-based UV sensors.
Optical fibers are usually fabricated by molding or drawing techniques15. 3D printing or Additive manufacturing (AM) is a new technology in fabricating tailored photonic components16. For manufacturing 3D printed polymer parts, different types of 3D printers are used, such as Stereolithographic apparatus (SLA), Digital laser printing (DLP), and Fused filament fabrication (FFF). The simplest method to get functionalized polymer optical fiber (POF) is by adding a stimuli-sensitive material in the resin17. Depending upon stimuli-sensitive material, the functionalized POF can respond to different stimuli, such as pH, temperature, light, stress, ions, and many more. The interaction between functionalized POF and external stimuli can result in physical or chemical changes in POF, which eventually alters the optical response16. 3D printed optical fibers are generally used for biological sensing applications18,19. Alam et al.17 developed 3D printed hydrogel optical fibers for temperature sensing. To the best of our knowledge, no research had been conducted on 3D printed optical fibers for UV sensing application. Photochromic powders offer an alternative for nanoparticles production, which eases the manufacturing process and production cost. 3D printing also allows sensors to be customized using different photochromic powders for accurate sensing. 3D printed UV sensing optical fibers represent an innovative fusion of additive manufacturing and photonics, providing a platform for the creation of responsive and adaptable sensors for ultraviolet radiation. These fibers not only enable real-time UV detection but also offer the unique capability to alter their properties in response to environmental changes, opening up possibilities for advanced monitoring and precision applications.
In this study, UV sensing hydrogel polymer optical fibers were fabricated by a DLP 3D printer, and reversible UV-sensitive powders20 were added as a sensing element in photocurable resin consisting of a 1:1 ratio of polyhydroxymethyl methacrylate (pHEMA) and polyethylene glycol diacrylate (PEGDA). Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) techniques were used to understand the fabricated OF’s material properties. The UV-sensitive powders displayed colorimetric changes according to the UV light exposure and alter the optical signals propagating through the optical fiber. The transmission and reflection through the optical fiber under white light and UV exposure were investigated. The change in the optical signal upon UV exposure was measured and correlated with UV sensing.
Hydroxymethyl methacrylate (HEMA, ≥ 99% purity, Sigma-Aldrich) and polyethylene glycol diacrylate (PEGDA, ≥ 99% purity, Sigma-Aldrich) were used as starting polymer raw materials. Trimethoxylbenzoyl phosphine oxide (TPO, ≥ 99% purity, Sigma-Aldrich) is used as a photoinitiator. Two different types of UV-sensitive powder; pink and blue are obtained from the UAE-based Amazon brand. Isopropyl alcohol (≥ 99% purity, Merck kGaA Germany) is used as a cleaning agent.
The HEMA and PEGDA were taken by a ratio of 1:1 (by weight) in a beaker for preparing UV-curable polymer resin for 3D printing of optical fiber. A 3 wt.% TPO is added as a photoinitator and mixed using a magnetic stirrer at a speed of 500 rpm at room temperature for 30 min. HEMA is a biocompatible and flexible polymer, whereas PEGDA is a long-chained polymer that helps to crosslink HEMA. The photoinitiator TPO initiates photopolymerization in the presence of UV light, of wavelength ranging from 385 to 420 nm. This HEMA/PEGDA hydrogel resin is used for the fabrication of transparent samples, with optimum mechanical and optical transmisison properties. To obtain photocurable UV sensing resin, 0.1 wt.% of UV powders; pink, blue, and a mixture of pink and blue were added at the stirring state (Fig. 1a). Finally, four different types of polymer composites and printed fiber samples were produced for this work: clear (HEMA/PEGDA only), pink (HEMA/PEGDA + 0.1% pink powder), blue (HEMA/PEGDA + 0.1% blue powder), and pink + blue (HEMA/PEGDA + 0.05% pink and 0.05% blue powders).
(a) Fabrication of 3D printed optical fiber, (b) slicing of fiber structure for 3D printing, (c) 3D printed samples, (d) effect of printing orientations in CAD model and slicing, (e) optical microscopic images of POF without powder in horizontal and vertical printing, (f) Optical microscopic images of POF with pink UV powder in horizontal and vertical printing.
The 3D printing design of optical fibers with a diameter of 3 mm and lengths of 1 cm, 2 cm, and 3 cm, was made using lychee slicer software in both horizontal and vertical orientations as shown in Fig. 1b. The model is sliced into the required format (.pwma) file for compatibility with the 3D printer and the detailed printing parameters are shown in Table 1. Anycubic photon mono 4 k 3D printer having a resolution of 3840 × 2400 px was used to print high-transpaent and mechanically robust optical fibers. This 3D printer has an exposure screen of 6.23 inches and maximum printable dimensions of 165 × 132 × 80 mm (HWD). This printer utilises a UV light source of wavelength of 405 nm which is within the range of added photoinitiator’s activation wavelengths. The resin is poured into the resin bath and the required program is selected to print the optical fiber. After 3D printing, the printed parts are removed and UV cured (post-printing) using a UV curing machine for additional 20 min to cure any uncured regions. The samples are then cleaned in isopropanol by using an ultrasonicator for 20 min (Fig. 1a). The obtained POF samples in both horizontal and vertical orientations are shown in Fig. 1c.
3D printed samples are characterized using spectroscopic and microscopic techniques and tested using a customised optical setup. The spectroscopic analysis of UV powder and 3D printed samples was carried out by an X-ray diffractometer (XRD, PANalytical Empyrean) operating at a voltage of 45 kV and current of 40 mA from a 5 to 80-degree angle. Fourier transfer infrared spectroscopy (FTIR) was used to investigate the chemical structure of the printed samples from 400 to 4000 cm−1. The surface of 3D printed optical fibers was analyzed using a scanning electron microscope (SEM, FEI Nova NanoSEM) at an operating voltage of 20 kV and a working distance of 4 mm. The optical fiber surface was coated with a thin layer of gold by a sputter coating machine to make the surface conductive and to avoid charge accumulation. The optical characterization of 3D printed fibers was examined by an optical microscope (OM, AXIO Scope1 Germany). A UV–Vis spectrometer (USB 2000 +), using OceanART software with an operating wavelength of 400–1100 nm, was employed to investigate the transmission and reflection spectra of the optical fibers. A monochromatic UV light source of 385 nm waelength was used to measure the optical fiber’s switching response under UV exposure. A green laser of 532 nm wavelength was used to measure the sensor’s response time, and a power meter (Thorlabs power monitor) was utilized to measure the transmitted power.
The effect of slicing on the surface morphology of the polymers can be seen in Fig. 1d, e, and f. In the horizontal clear sample, the lines represent the layers in 3D printing. On the other hand, no lines are visible in the vertically printed sample as the slicing was parallel to the circular surface. In the pink POF, spherical particles also can be seen embedded within the polymer matrix.
The X-ray diffraction patterns of pink and blue UV powders are illustrated in Fig. 2a. From the plot, it is clear that the powders are crystalline materials with similar chemical compositions. In the insert, the color change exhibited by the UV powders can be observed when exposed to UV light. The white powders (original color) transition into pink and blue on UV exposure and revert to back to white appearance when the UV light is removed. The photochromic dyes undergo reversible changes in their molecular structure in response to UV exposure. These changes cause a shift in the dye’s absorption properties, leading to its color alterations. When the dye is exposed to UV light, the dye absorbs the photons and undergoes a photochemical reaction, resulting in a color change21. This change in color is temporary and reversible; once the UV light is removed or the dye is shielded from UV, it gradually returns to its original color. The specific color change of a photochromic dye depends on its molecular structure and the wavelength of the light it interacts with. The ability of photochromic dyes to reversibly change color in response to light makes them valuable for various applications, including in optical sensors, light-responsive materials, and photochromic eyewear for UV protection. Figure 2a indicates the pale white photochromic powders changing to their respective pink and blue colors under UV light. Figure 2b & c shows the SEM images of the pink and blue UV powders, respectively. The powders have a core–shell structure and have an average diameter of 2–5 µm for pink powder and 3–6 µm for blue powder. Also, it is clear that there is no significant difference in the morphology of the powders.
(a) XRD pattern of pink and blue UV powder, (b) and (c) SEM images of pink and blue UV powders, respectively, (d) XRD pattern of 3D printed POF, (e) and (f) SEM images of 3D printed clear and pink powder added POF, (g) FTIR spectra of 3D printed POF, (h) color change of 3D printed POF under UV light, (i) complementary color wheel.
The XRD patterns of 3D printed fibers from clear and UV powder doped resins are depicted in Fig. 2d. A slightly higher intensity of peaks can be observed for the clear POF. This might be because of the larger pore sizes in clear polymer compared to the composite membranes, where pore sites are likely occupied by the added photochromic powders22. In composite fibers, there is a high chance for the additive to occupy the pore sites in the polymer. However, no peaks are observed that can be attributed to the UV powder in the polymer. This might be because of the low concentration of additives added16,23. The XRD also shows that no additional phases were formed during the 3D printing process.
Figure 2e and f represents the surface morphology of 3D printed clear and pink polymer composite using SEM images. In the clear fiber, the layers are fused together with no impurities. The TPO, pHEMA, and PEGDA are blended consistently within the polymer. In the pink POF, the powder is homogenously distributed with low agglomeration. Also, the spherical particles retained their shape in the matrix without any distortion.
Figure 2g depicts the FTIR spectra of 4D printed samples and the major peaks are observed at wavenumbers 1077, 1092, 1155, 1274, 1455, and 1718 cm−1. The peak at 1077 and 1092 cm−1 corresponds to C–O stretching, and the peak at 1155 cm−1 corresponds to the vibration of the C–C–OH group. The peaks at 1274, 1455, and 1718 cm-1 represent the stretching of C–O–C, C–H, and C=O functional groups, respectively. In addition, a narrower band from 2800 to 2980 cm−1 shows the presence of C–H stretching in the polymer matrix. The broader band from 3100 to 3600 cm−1 is due to the stretching of the O–H functional group24,25,26. There is no significant peak shift observed in UV powder-added samples from pure pHEMA/PEGDA samples and the polymer phase is confirmed in all fibers.
Figure 2h shows the photographic image of 3 cm printed fibers in with and without UV exposure. Both pink and blue POF show significant colorimetric change while the color change in the mixed powder fiber is minimal. This might be due to a combination of the dilution effect and neutralizing of the colors. It is caused when the concentration of individual powder is reduced when mixing powders. When one has a more intense UV-reactive color while the other is relatively inert, the combined mixture might appear paler due to the overall reduction in intensity27,28. When the two powders with complementary or neutralizing colors are mixed, the resulting color might appear paler due to the cancelation or desaturation of certain wavelengths29,30. The pie diagram in Fig. 2i represents the complementary color wheel of visible light from a wavelength of 400–800 nm. When light is passed through a material, a portion of the light is absorbed and the transmitted wavelength gives the complementary color to the materials. For example, if a material absorbs blue light, the material will appear to be orange. According to the color chart, the observance of the pink and blue color of the POF fibers shows that the fibers absorb wavelengths around 560 and 600 nm respectively. The absorption spectrum of the pink dye shows that it absorbs light in the UV region, typically within the range of 300–400 nm. When exposed to UV radiation within this wavelength range, the dye undergoes a reversible photochemical reaction, leading to a color change towards pink. In the case of the blue powder, the corresponding wavelength of light is between 580 and 620 nm. The intensity of color changes in the case of powder and when it is added to POF also varies. In the powder form, the color changes to deep blue and pink, while when added to POF, it is lighter shades of blue and pink. The low concentration of the powder and the dilution effect of the hydrogel matrix is the reason for this. Also, the uniform color throughout the fiber indicates the homogenous dispersion of photochromic powders through the polymer matrix.
Figure 3a shows the schematic of the reflection measurement setup of the 3D-printed POF. Reflection spectra of 1 cm, 2 cm, and 3 cm POF with and without UV powders were measured. A mirror is placed under the POF to increase the reflection signal, and UV light is shone from the side to excite UV powders in the printed fiber. The reflection spectra of horizontally printed POFs with 1 cm, 2 cm, and 3 cm lengths are shown in Fig. 3b, c, and d, respectively. A glass slide is used as a reference. A decreasing trend in reflection spectra with increasing fiber length is clearly visible. For the clear fiber, there is a decrease of approximately 5% in reflectance from 72.5 to 68% when the length is increased from 1 to 3 cm. For the fibers with the photochromic powder, a loss in reflectance between 20 and 40% can be observed when the length is increased. The maximum loss in reflectance is observed for pink fiber in the presence of UV irradiation. Its reflectance fell from ~ 60 to 20% when the length is increased. This decrease can be attributed to the optical losses as hydrogel exhibits higher light absorption and scattering compared to conventional glass fibers31. As the fiber length increases, light encounters more interactions with the hydrogel medium, resulting in higher absorption and scattering losses31,32. Additionally, hydrogel materials can undergo changes in refractive index due to additives, causing light to be refracted or reflected at different angles, leading to further losses33. Moreover, interfaces between the hydrogel material and added fillers introduce additional reflection losses34,35. The reflection loss in the fiber is more significant for pink fibers and the lowest for clear fibers. This might be due to the addition of micro-sized particles causing multiple scattering and refractive index mismatches36,37 leading to loss of reflection38. When micro-sized particles are incorporated into the hydrogel matrix, they can introduce irregularities and inhomogeneity in the material, leading to increased light scattering as photons encounter these particles36. The scattering effect deviates light from its original path, resulting in reduced coherence and intensity of the reflected signal. Additionally, the refractive index of the micro-sized particles might differ significantly from that of the hydrogel, causing abrupt changes at the interfaces and leading to additional reflection losses38,39.
(a) Experimental setup of reflection measurement using visible light, (b), (c) and (d) are reflection spectra of horizontally printed fibers having lengths 1 cm, 2 cm, and 3 cm, respectively, (e), (f) and (g) are reflection spectra of vertically printed fibers having length 1 cm, 2 cm, and 3 cm respectively.
Under 385 nm wavelength UV light exposure, no change in the spectrum of clear fiber is observed. But a dip at 570, 620, and 590 nm is observed in the case of pink, blue, and mixed POF. These dips corroborate with the color wheel (Fig. 2i). The reflection is more prominent in vertically printed fibers than horizontally printed fibers (Fig. 3e–g). The reflectance of the horizontally printed clear optical fiber of 1 cm is 80% while the reflectance in the vertically printed fiber of the same configuration is 75% (Fig. 3e). Similar changes in reflectance can be observed for all optical fibers. It is because the printed layers are perpendicular to the direction of light travel. It increases the reflection from each layer, whereas, in horizontally printed samples, parallel layers enhance transmission16,40,41. In horizontally printed optical fibers, the parallel layers act as parallel waveguides supporting the propagation modes through the fiber, resulting in a multi-mode optical fiber. On the other hand, in the vertically printed optical fibers, layers are perpendicular to the light propagation direction, causing backscattering and reflection of light at each new layer interface. Even though there is a variation in the intensity of the reflection, both the vertically printed and horizontally printed POF shows a similar trend of reflection loss with respect to increasing fiber length. The print orientation also does not affect the UV dip in the spectra.
Figure 4a depicts the transmission measurement setup for POFs. Transmission spectra of all printed POF with and without UV powder were measured within the visible range (400–750 nm). Figure 4b, c, and d show the transmission spectra of horizontally printed fibers of 1 cm, 2 cm, and 3 cm length, respectively. Figure 4e, f, and g depicts the transmission spectra of vertically printed fibers with 1 cm, 2 cm, and 3 cm lengths, respectively. Similar to the reflection spectra, the transmission spectra also show dips at 570, 620, and 590 nm. However, the horizontally printed fiber shows more transmission in all cases compared to vertically printed fibers. Horizontally printed optical fibers exhibit parallel layers that act as waveguides, supporting multiple propagation modes and resulting in a multi-mode fiber structure. In the case of absorbance, a reverse of reflectance can be observed with horizontal and vertical printed fiber. Therefore, the print direction significantly influences the transmission characteristics of 3D printed hydrogel optical fibers, with horizontal printing offering better transmission performance compared to vertical printing16. When exposed to UV light, the photochromic molecules undergo reversible chemical changes, altering their absorption properties. As UV light interacts with the composite material, the photochromic molecules absorb specific wavelengths, changing transmission spectra. In the case of pink, blue, and mixed POF, the transmission and reflection spectra show the dip at 570, 620, and 590 nm upon exposure to UV light. By comparing the altered spectra with the baseline spectra (without UV exposure), the UV exposure levels can be accurately determined. The reflection and transmittance spectra shifts provide valuable information about the UV radiation intensity, enabling precise and real-time UV monitoring. This sensing approach has applications in various fields, including UV dosimetry, environmental monitoring, and industrial processes, thanks to its sensitivity, non-invasive nature, and remote sensing capabilities.
(a) Experimental setup of transmission measurement using visible light, (b), (c) and (d) are transmission spectra of horizontally printed fibers having lengths 1 cm, 2 cm, and 3 cm respectively, (e), (f) and (g) are transmission spectra of vertically printed fibers having lengths 1 cm, 2 cm, and 3 cm respectively.
Figure 5 illustrates the use of a green laser (532 nm) for measuring the changes in power and response time of the POF with respect to UV exposure. The setup includes the use of a laser pointer, photodetector, and power meter. The green laser was coupled to the printed fiber, and the transmitted laser power was measured. As the green laser interacts with the photochromic composite and UV light is present, the photochromic molecules undergo specific changes in their absorption properties. This leads to the difference in the transmitted power. By monitoring the variations in transmitted power, we can precisely use it for UV sensing applications. Figure 5b, c, and d depicts the response time for UV exposure in terms of transmitted power for horizontally printed POFs. The POF loaded with pink powder added POF shows a quick response to the UV light and changes color rapidly. This might be due to the smaller size of pink powders as observed via SEM and its homogenous dispersion through the matrix, causing larger changes in the refractive index within the polymer42,43. Under UV light, the material absorbs specific wavelengths reducing transmitted power. After that UV is switched off the POF reverts back to its original color. This reversible change happens in a certain time (response time) which was recorded using a stopwatch for both exposures to UV and upon the removal of UV. It is observed that the pink-POF has a lower response time under UV, and a higher reversal time to revert back to its original state compared to blue OF. This is true across all lengths, even though the time increases from 4 to 6 s when the length increases. The POF containing the mixture of both powders shows the highest response and retraction time compared to the other two types of fibers. Here also, the response and retraction time increases with increasing length.
(a) Experimental setup of measuring UV response time of POF using green laser, (b), (c) and (d) are transmitted power of horizontally printed fibers in three cycle having lengths 1 cm, 2 cm, and 3 cm respectively, (e), (f) and (g) are transmitted power of vertically printed fibers in three cycle having lengths 1 cm, 2 cm, and 3 cm respectively, (h) and (i) A comparison of the transmitted power of horizontally printed POFs in normal and UV environments (j) The optical fiber transmission under ambient conditions and UV exposure.
Figure 5d, e, and f depict the response time for UV exposure in terms of transmitted power for vertically printed POFs. It also shows a similar trend in transmitted power to that of horizontally printed fiber. The only difference is that the transmitted power is less in vertical orientations than in horizontal ones. Figure 5h and i illustrate the comparison of the transmitted power of horizontally and vertically printed POFs in normal and UV environments. In all cases, the transmitted power is lower under UV exposure, and power is reduced with increasing fiber length. There is also a slight decrease in power when the fibers are horizontally printed. This might be due to the loss of laser reflection within the horizontally printed slicing layers. To ensure the repeatability and longevity of the fibers, the POF underwent multiple UV exposure cycles. Figure 5j shows digital photographs illustrating the reversible color variation in the pink optical fiber after UV exposure, provided for illustration purposes only.
The proposed UV sensor based on hydrogel polymer optical fiber offers several advantages over conventional optical fiber UV sensors. Most of the optical UV fibers are using surface plasmon resonance mechanism or scintillating materials to detect UV radiation. Compared to those work, utilizing a 3D printed hydrogel composite sensor with micro-sized photochromic dyes, provides flexible and precise detection of UV radiation. In this work the photochromic dyes embedded in the hydrogel exhibit specific absorption characteristics upon UV exposure, leading to significant decreases in reflection and transmittance at distinct wavelengths (560 nm, 620 nm, and 590 nm). Also, the manufacturing process, employing digital light processing 3D printing, allows for the fabrication of optical fibers in various lengths and orientations, enhancing customization and application flexibility. The ability to tailor the response and retraction times, along with the impact of printing orientation on optical performance, underscores the comprehensive sensing capabilities and adaptability of these hydrogel-based UV sensors.
In conclusion, this investigation demonstrates the successful development of UV-sensing 3D printed POF with unique optical characteristics. The presence of characteristic dips at 560 nm, 620 nm, and 590 nm in both reflection and transmittance spectra highlights the distinct response of the photochromic materials to UV light. The pink, blue, and mixed photochromic powders enable versatile UV dosimetry, showcasing the potential for tailored UV sensing applications. Furthermore, our investigation into the effect of fiber length on the sensing properties reveals exciting trends. As the fiber length increases, we observe variations in power in response to UV exposure. Notably, the pink powder demonstrates a higher power change compared to the other photochromic dyes, indicating its superior sensitivity to UV radiation (Supplementary information).
These findings underscore the significance of 3D printing technology in fabricating customizable optical fiber hydrogels for UV sensing applications. The tunable color responses of the photochromic dyes offer exciting prospects for targeted UV dosimetry in different environmental conditions. The versatility and remote sensing capabilities of these fibers make them attractive candidates for a wide range of applications, including environmental monitoring, healthcare diagnostics, and industrial safety.
The optical spectroscopic data analyzed during the current study is available from the corresponding authors on reasonable request.
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The authors acknowledge Sandooq Al Watan LLC for the research funding (SWARD Program—AWARD, Project code: 8434000391-EX2020-044). We also acknowledge Khalifa University for the research funding (Award No. RCII-2019-003) in support of this research.
Department of Mechanical and Nuclear Engineering, Khalifa University of Science and Technology, Abu Dhabi, 127788, United Arab Emirates
Dileep Chekkaramkodi, Israr Ahmed, Liya Jacob & Haider Butt
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Dileep Chekkaramkodi wrote the first draft and let the projects experimental work. Israr Ahmed performed the optical fiber characterizations and setup preparations. Liya Jacob aided in the materials preparation and also edited the manuscript. Haider Butt conceptulaised the project, supervised the project and edited the draft.
Correspondence to Dileep Chekkaramkodi or Haider Butt.
The authors declare no competing interests.
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Chekkaramkodi, D., Ahmed, I., Jacob, L. et al. 3D printed UV-sensing optical fiber probes: manufacturing, properties, and performance. Sci Rep 14, 19001 (2024). https://doi.org/10.1038/s41598-024-69872-9
DOI: https://doi.org/10.1038/s41598-024-69872-9
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