This paper presents the development of a bioinspired multifunctional flexible optical sensor (BioMFOS) as an ultrasensitive tool for force (intensity and location) and orientation sensing. The sensor structure is bioinspired in orb webs, which are multifunctional devices for prey capturing and vibration transmission. The multifunctional feature of the structure is achieved by using transparent resins that present both mechanical and optical properties for structural integrity and strain/deflection transmission as well as the optical signal transmission properties with core/cladding configuration of a waveguide. In this case, photocurable and polydimethylsiloxane (PDMS) resins are used for the core and cladding, respectively. The optical transmission, tensile tests, and dynamic mechanical analysis are performed in the resins and show the possibility of light transmission at the visible wavelength range in conjunction with high flexibility and a dynamic range up to 150 Hz, suitable for wearable applications. The BioMFOS has small dimensions (around 2 cm) and lightweight (0.8 g), making it suitable for wearable application and clothing integration. Characterization tests are performed in the structure by means of applying forces at different locations of the structure. The results show an ultra-high sensitivity and resolution, where forces in the μN range can be detected and the location of the applied force can also be detected with a sub-millimeter spatial resolution. Then, the BioMFOS is tested on the orientation detection in 3D plane, where a correlation coefficient higher than 0.9 is obtained when compared with a gold-standard inertial measurement unit (IMU). Furthermore, the device also shows its capabilities on the movement analysis and classification in two protocols: finger position detection (with the BioMFOS positioned on the top of the hand) and trunk orientation assessment (with the sensor integrated on the clothing). In both cases, the sensor is able of classifying the movement, especially when analyzed in conjunction with preprocessing and clustering techniques. As another wearable application, the respiratory rate is successfully estimated with the BioMFOS integrated into the clothing. Thus, the proposed multifunctional device opens new avenues for novel bioinspired photonic devices and can be used in many applications of biomedical, biomechanics, and micro/nanotechnology.
|||Akpakwu GA, Silva BJ, Hancke GP, Abu-Mahfouz AM. A survey on 5G networks for the internet of things: communication technologies and challenges. IEEE Access 6, 3619–3647 (2017). doi: 10.1109/ACCESS.2017.2779844|
|||Shafique K, Khawaja BA, Sabir F, Qazi S, Mustaqim M. Internet of things (IoT) for next-generation smart systems: a review of current challenges, future trends and prospects for emerging 5G-IoT scenarios. IEEE Access 8, 23022–23040 (2020). doi: 10.1109/ACCESS.2020.2970118|
|||Li SC, Xu LD, Zhao SS. 5G internet of things: a survey. J Ind Inf Integr 10, 1–9 (2018). doi: 10.1016/j.jii.2018.01.005|
|||Sicari S, Rizzardi A, Coen-Porisini A. 5G in the internet of things era: an overview on security and privacy challenges. Comput Netw 179, 107345 (2020). doi: 10.1016/j.comnet.2020.107345|
|||Kim MG; Brown DK, Brand O. Nanofabrication for all-soft and high-density electronic devices based on liquid metal. Nat Commun 11, 1002 (2020). doi: 10.1038/s41467-020-14814-y|
|||Wang Z, Yi SY, Chen A, Zhou M, Luk TS et al. Single-shot on-chip spectral sensors based on photonic crystal slabs. Nat Commun 10, 1020 (2019). doi: 10.1038/s41467-019-08994-5|
|||Chen Q, Liang L, Zheng Q L, Zhang Y X, Wen L. On-chip readout plasmonic mid-IR gas sensor. Opto-Electron Adv 3, 190040 (2020). doi: 10.29026/oea.2020.190040|
|||Washburn AL, Bailey RC. Photonics-on-a-chip: recent advances in integrated waveguides as enabling detection elements for real-world, lab-on-a-chip biosensing applications. Analyst 136, 227–236 (2011). doi: 10.1039/c0an00449a|
|||Martens D, Ramirez-Priego P, Murib MS, Elamin AA, Gonzalez-Guerrero AB et al. A low-cost integrated biosensing platform based on SiN nanophotonics for biomarker detection in urine. Anal Methods 10, 3066–3073 (2018). doi: 10.1039/c8ay00666k|
|||Jindal SK, Raghuwanshi SK, Kumar A. Realization of MOEMS pressure sensor using mach zehnder interferometer. J Mech Sci Technol 29, 3831–3839 (2015). doi: 10.1007/s12206-015-0829-z|
|||Lu QB, Wang YN, Wang XX, Yao Y, Wang XW et al. Review of micromachined optical accelerometers: from mg to sub-μg. Opto-Electron Adv 4, 200045 (2021). doi: 10.29026/oea.2021.200045|
|||Zhao ZH, Yu ZH, Chen K, Yu QX. A fiber-optic fabry-perot accelerometer based on high-speed white light interferometry demodulation. J Light Technol 36, 1562–1567 (2018). doi: 10.1109/JLT.2017.2783882|
|||Liu QP, Qiao XG, Jia ZA, Fu HW, Gao H et al. Large frequency range and high sensitivity fiber bragg grating accelerometer based on double diaphragms. IEEE Sens J 14, 1499–1504 (2014). doi: 10.1109/JSEN.2013.2296932|
|||Lee GH, Moon H, Kim H, Lee GH, Kwon W et al. Multifunctional materials for implantable and wearable photonic healthcare devices. Nat Rev Mater 5, 149–165 (2020). doi: 10.1038/s41578-019-0167-3|
|||Leal-Junior AG, Diaz CAR, Avellar LM, Pontes MJ, Marques C et al. Polymer optical fiber sensors in healthcare applications: a comprehensive review. Sensors 19, 3156 (2019). doi: 10.3390/s19143156|
|||Leal-Junior A, Avellar L, Frizera A, Marques C. Smart textiles for multimodal wearable sensing using highly stretchable multiplexed optical fiber system. Sci Rep 10, 13867 (2020). doi: 10.1038/s41598-020-70880-8|
|||Leal-Junior A, Guo JJ, Min R, Fernandes AJ, Frizera A et al. Photonic smart bandage for wound healing assessment. Photon Res 9, 272–280 (2021). doi: 10.1364/prj.410168|
|||Tan HW, Zhou YF, Tao QZ, Rosen J, van Dijken S. Bioinspired multisensory neural network with crossmodal integration and recognition. Nat Commun 12, 1120 (2021). doi: 10.1038/s41467-021-21404-z|
|||Kang D, Pikhitsa PV, Choi YW, Lee C, Shin SS et al. Ultrasensitive mechanical crack-based sensor inspired by the spider sensory system. Nature 516, 222–226 (2014). doi: 10.1038/nature14002|
|||Aoyanagi Y, Okumura K. Simple model for the mechanics of spider webs. Phys Rev Lett 104, 038102 (2010). doi: 10.1103/PhysRevLett.104.038102|
|||Jiang YH, Nayeb-Hashemi H. Dynamic response of spider orb webs subject to prey impact. Int J Mech Sci 186, 105899 (2020). doi: 10.1016/j.ijmecsci.2020.105899|
|||Lakes R. Viscoelastic Materials (Cambridge: Cambridge University Press, 2009);http://doi.org/10.1017/CBO9780511626722.|
|||Soler A, Zaera R. The secondary frame in spider orb webs: the detail that makes the difference. Sci Rep 6, 31265 (2016). doi: 10.1038/srep31265|
|||Mortimer B, Soler A, Siviour CR, Zaera R, Vollrath F. Tuning the instrument: sonic properties in the spider’s web. J Roy Soc Interface 13, 20160341 (2016). doi: 10.1098/rsif.2016.0341|
|||Junior AGL, Frizera A, Pontes MJ. Analytical model for a polymer optical fiber under dynamic bending. Opt Laser Technol 93, 92–98 (2017). doi: 10.1016/j.optlastec.2017.02.009|
|||Kaewunruen S, Ngamkhanong C, Yang TY. Large-amplitude vibrations of spider web structures. Appl Sci 10, 6032 (2020). doi: 10.3390/app10176032|
|||Jolliffe IT, Cadima J. Principal component analysis: a review and recent developments. Philos Trans Roy Soc A:Math, Phys Eng Sci 374, 20150202 (2016). doi: 10.1098/rsta.2015.0202|
|||Zheng LY, Behrooz M, Li R, Wang XJ, Gordaninejad F. Performance of a bio-inspired spider web. Proc SPIE 9057, 90570I (2014). doi: 10.1117/12.2046379|
|||White JR. Polymer ageing: physics, chemistry or engineering? Time to reflect. Comptes Rendus Chim 9, 1396–1408 (2006). doi: 10.1016/j.crci.2006.07.008|
|||Ma LY, Wu RH, Patil A, Zhu SH, Meng ZH et al. Full-textile wireless flexible humidity sensor for human physiological monitoring. Adv Funct Mater 29, 1904549 (2019). doi: 10.1002/adfm.201904549|
Supplementary information for Multifunctional flexible optical waveguide sensor: on the bioinspiration for ultrasensitive sensors development
Schematic representation of the sensor structure with the frame and radial elements. Figure also shows the mechanical representation of the structure with a mass on the center.
(a) Schematic representation of the core/cladding fabrication steps. (b) Representation of the batteries and µLED assembly in the structure, which is used as the light source of the optical system and proof mass of the structural design. Figure also shows a photograph of the BioMFOS.
Optical and mechanical characterizations of the resins (photocurable and PDMS resins). Transmittance spectra, Stress-strain curves, and DMA results are presented.
Transmitted optical power (converted into voltage in the photodetector unit) as a function of the applied force in different positions of the PDMS matrix. Figure also shows the force sensitivity of the sensors.
(a) Comparison between the BioMFOS responses (of three radial elements) and IMU for different positions/orientations in 3D plane. The directions of the orientation planes (roll, pitch, and yaw) are also shown. Figure inset shows the positions of the radial elements used in these tests. (b) Optical signal variation of 3 radial elements (sensors 1 to 3) as a function of the finger position, markers and bars represent the mean and standard deviation of the tests, respectively.
(a) Respiration rate assessment using the BioMFOS. (b) Trunk position classification using the BioMFOS integrated into clothing and PCA results for each trunk position.