[1] Wei, Y. Z. & Xu, Q. S. An overview of micro-force sensing techniques. Sens. Actuators A Phys. 234, 359–374 (2015). doi: 10.1016/j.sna.2015.09.028
[2] Conrad, H. et al. A small-gap electrostatic micro-actuator for large deflections. Nat. Commun. 6, 10078 (2015). doi: 10.1038/ncomms10078
[3] Xie, Y. et al. Development of a microforce sensor and its array platform for robotic cell microinjection force measurement. Sensors 16, 483 (2016). doi: 10.3390/s16040483
[4] Uhrig, K. et al. Optical force sensor array in a microfluidic device based on holographic optical tweezers. Lab Chip 9, 661–668 (2009). doi: 10.1039/b817633g
[5] Hu, Z. M. et al. Optocapillarity-driven assembly and reconfiguration of liquid crystal polymer actuators. Nat. Commun. 11, 5780 (2020). doi: 10.1038/s41467-020-19522-1
[6] Guo, H. C. et al. Artificially innervated self-healing foams as synthetic piezo-impedance sensor skins. Nat. Commun. 11, 5747 (2020). doi: 10.1038/s41467-020-19531-0
[7] Zhu, Q. D. et al. A double‐layer mechanochromic hydrogel with multidirectional force sensing and encryption capability. Adv. Funct. Mater. 29, 1808191 (2019). doi: 10.1002/adfm.201808191
[8] Šiškins, M. et al. Sensitive capacitive pressure sensors based on graphene membrane arrays. Microsyst. Nanoeng. 6, 102 (2020). doi: 10.1038/s41378-020-00212-3
[9] Sun, T. et al. Decoding of facial strains via conformable piezoelectric interfaces. Nat. Biomed. Eng. 4, 954–972 (2020). doi: 10.1038/s41551-020-00612-w
[10] Han, X. G. et al. Novel resonant pressure sensor based on piezoresistive detection and symmetrical in-plane mode vibration. Microsyst. Nanoeng. 6, 95 (2020). doi: 10.1038/s41378-020-00207-0
[11] Pevec, S. & Donlagic, D. Miniature all-fiber force sensor. Opt. Lett. 45, 5093–5096 (2020). doi: 10.1364/OL.401690
[12] Thompson, A. J., Power, M. & Yang, G. Z. Micro-scale fiber-optic force sensor fabricated using direct laser writing and calibrated using machine learning. Opt. Express 26, 14186–14200 (2018). doi: 10.1364/OE.26.014186
[13] Li, M. et al. Ultracompact fiber sensor tip based on liquid polymer-filled Fabry-Perot cavity with high temperature sensitivity. Sens. Actuators B Chem. 233, 496–501 (2016). doi: 10.1016/j.snb.2016.04.121
[14] Huang, J. Q. et al. Operando decoding of chemical and thermal events in commercial Na(Li)-ion cells via optical sensors. Nat. Energy 5, 674–683 (2020). doi: 10.1038/s41560-020-0665-y
[15] Wu, Y. et al. Highly sensitive force sensor based on balloon-like interferometer. Opt. Laser Technol. 103, 17–21 (2018). doi: 10.1016/j.optlastec.2018.01.008
[16] Shen, C. Y. et al. Measurements of milli-Newton surface tension forces with tilted fiber Bragg gratings. Opt. Lett. 43, 255–258 (2018). doi: 10.1364/OL.43.000255
[17] Jia, Y. P. et al. Complementary chiral metasurface with strong broadband optical activity and enhanced transmission. Appl. Phys. Lett. 104, 011108 (2014). doi: 10.1063/1.4861422
[18] Farsari, M. & Chichkov, B. N. Two-photon fabrication. Nat. Photonics 3, 450–452 (2009). doi: 10.1038/nphoton.2009.131
[19] Schaedler, T. A. et al. Ultralight metallic microlattices. Science 334, 962–965 (2011). doi: 10.1126/science.1211649
[20] Kim, S. et al. A two-step fabrication method for 3D printed microactuators: characterization and actuated mechanisms. J. Microelectromech. Syst. 29, 544–552 (2020). doi: 10.1109/JMEMS.2020.2992367
[21] Cumpston, B. H. et al. Two-photon polymerization initiators for three-dimensional optical data storage and microfabrication. Nature 398, 51–54 (1999). doi: 10.1038/17989
[22] Power, M. et al. A monolithic force-sensitive 3D microgripper fabricated on the tip of an optical fiber using 2-photon polymerization. Small 14, 1703964 (2018). doi: 10.1002/smll.201703964
[23] Kelemen, L. et al. Direct writing of optical microresonators in a lab-on-a-chip for label-free biosensing. Lab a Chip 19, 1985–1990 (2019). doi: 10.1039/C9LC00174C
[24] Xu, B. et al. High efficiency integration of three-dimensional functional microdevices inside a microfluidic chip by using femtosecond laser multifoci parallel microfabrication. Sci. Rep. 6, 19989 (2016). doi: 10.1038/srep19989
[25] Vanderpoorten, O. et al. Scalable integration of nano-, and microfluidics with hybrid two-photon lithography. Microsyst. Nanoeng. 5, 40 (2019). doi: 10.1038/s41378-019-0080-3
[26] Li, B. et al. A bio-inspired 3D micro-structure for graphene-based bacteria sensing. Biosens. Bioelectron. 123, 77–84 (2019). doi: 10.1016/j.bios.2018.09.087
[27] Marino, A. et al. Biomimicry at the nanoscale: current research and perspectives of two-photon polymerization. Nanoscale 7, 2841–2850 (2015). doi: 10.1039/C4NR06500J
[28] Hippler, M. et al. 3D scaffolds to study basic cell biology. Adv. Mater. 31, 1808110 (2019). doi: 10.1002/adma.201808110
[29] Villangca, M. J. et al. Light-driven micro-tool equipped with a syringe function. Light. Sci. Appl. 5, e16148 (2016). doi: 10.1038/lsa.2016.148
[30] Ma, Z. C. et al. Femtosecond laser programmed artificial musculoskeletal systems. Nat. Commun. 11, 4536 (2020). doi: 10.1038/s41467-020-18117-0
[31] Xiong, Z. et al. Magnetic-field-driven ultra-small 3D hydrogel microstructures: preparation of gel photoresist and two-photon polymerization microfabrication. Sens. Actuators B Chem. 274, 541–550 (2018). doi: 10.1016/j.snb.2018.08.006
[32] Wang, W. K. et al. Magnetic nickel–phosphorus/polymer composite and remotely driven three-dimensional micromachine fabricated by nanoplating and two-photon polymerization. J. Phys. Chem. C. 115, 11275–11281 (2011). doi: 10.1021/jp202644d
[33] Wang, H. et al. [INVITED] A miniaturized optical fiber microphone with concentric nanorings grating and microsprings structured diaphragm. Opt. Laser Technol. 78, 110–115 (2016). doi: 10.1016/j.optlastec.2015.08.009
[34] Melissinaki, V., Farsari, M. & Pissadakis, S. A fiber-endface, fabry–perot vapor microsensor fabricated by multiphoton polymerization. IEEE J. Sel. Top. Quantum Electron. 21, 5600110 (2015). doi: 10.1109/JSTQE.2014.2381463
[35] Xiong, C. et al. Fiber-tip polymer microcantilever for fast and highly sensitive hydrogen measurement. ACS Appl. Mater. Interfaces 12, 33163–33172 (2020). doi: 10.1021/acsami.0c06179
[36] Sun, L. D. et al. 3D-printed cellular tips for tuning fork atomic force microscopy in shear mode. Nat. Commun. 11, 5732 (2020). doi: 10.1038/s41467-020-19536-9
[37] Palacio, M. L. B. & Bhushan, B. Depth-sensing indentation of nanomaterials and nanostructures. Mater. Charact. 78, 1–20 (2013). doi: 10.1016/j.matchar.2013.01.009
[38] Chavan, D. et al. Ferrule-top nanoindenter: an optomechanical fiber sensor for nanoindentation. Rev. Sci. Instrum. 83, 115110 (2012). doi: 10.1063/1.4766959
[39] Li, C. et al. Femtosecond laser microprinting of a polymer fiber Bragg grating for high-sensitivity temperature measurements. Opt. Lett. 43, 3409–3412 (2018). doi: 10.1364/OL.43.003409
[40] Hua, Z., Wu, S. S. & Shen, J. Polymer/silica nanocomposites: preparation, characterization, properties, and applications. Chem. Rev. 39, 3893–3957 (2008). doi: 10.1021/cr068035q
[41] Liu, S. et al. High-sensitivity strain sensor based on in-fiber rectangular air bubble. Sci. Rep. 5, 7624 (2015). doi: 10.1038/srep07624
[42] Ding, W. Q., Guo, Z. Y. & Ruoff, R. S. Effect of cantilever nonlinearity in nanoscale tensile testing. J. Appl. Phys. 101, 034316 (2007). doi: 10.1063/1.2435064
[43] Namjoshi, K. V. & Biringer, P. P. Low-frequency eddy-current loss estimation in long conductors by using the moment of inertia of cross sections. IEEE Trans. Magn. 24, 2181–2185 (1988). doi: 10.1109/20.3426
[44] Balaji, V. & Bhat, K. N. A comparison of burst strength and linearity of pressure sensors having thin diaphragms of different shapes. J. ISSS 2, 18–26 (2012). http://www.isssonline.in/journal/02paper08.pdf
[45] Vangelatos, Z. et al. Investigating the mechanical response of microscale pantographic structures fabricated by multiphoton lithography. Extrem. Mech. Lett. 43, 101202 (2021). doi: 10.1016/j.eml.2021.101202
[46] White, I. M. & Fan, X. D. On the performance quantification of resonant refractive index sensors. Opt. Express 16, 1020–1028 (2008). doi: 10.1364/OE.16.001020
[47] Seghir, R. & Arscott, S. Extended PDMS stiffness range for flexible systems. Sens. Actuators A Phys. 230, 33–39 (2015). doi: 10.1016/j.sna.2015.04.011
[48] Chaudhury, M. K. et al. The influence of elastic modulus and thickness on the release of the soft-fouling green alga Ulva linza (syn. Enteromorpha linza) from poly (dimethylsiloxane) (PDMS) model networks. Biofouling 21, 41–48 (2005). doi: 10.1080/08927010500044377
[49] Butt, H. J. & Jaschke, M. Calculation of thermal noise in atomic force microscopy. Nanotechnology 6, 1 (1999). doi: 10.1088/0957-4484/6/1/001
[50] Galluzzi, M. et al. Space-resolved quantitative mechanical measurements of soft and supersoft materials by atomic force microscopy. NPG Asia Mater. 8, e327 (2016). doi: 10.1038/am.2016.170
[51] Sneddon, I. N. The relation between load and penetration in the axisymmetric boussinesq problem for a punch of arbitrary profile. Int. J. Eng. Sci. 3, 47–57 (1965). doi: 10.1016/0020-7225(65)90019-4
[52] Galluzzi, M. et al. Atomic force microscopy methodology and AFMech Suite software for nanomechanics on heterogeneous soft materials. Nat. Commun. 9, 3584 (2018). doi: 10.1038/s41467-018-05902-1
[53] Wei, G. H., Bhushan, B. & Torgerson, P. M. Nanomechanical characterization of human hair using nanoindentation and SEM. Ultramicroscopy 105, 248–266 (2005). doi: 10.1016/j.ultramic.2005.06.033
[54] Liu, Q. et al. High-sensitivity photonic crystal fiber force sensor based on Sagnac interferometer for weighing. Opt. Laser Technol. 123, 105939 (2020). doi: 10.1016/j.optlastec.2019.105939
[55] Chung, K. M. Highly sensitive compact force sensor based on microfiber bragg grating. IEEE Photonics Technol. Lett. 24, 700–702 (2012). doi: 10.1109/LPT.2012.2187049
[56] Liu, Y. et al. A Fabry–Perot cuboid cavity across the fibre for high-sensitivity strain force sensing. J. Opt. 16, 105401 (2014). doi: 10.1088/2040-8978/16/10/105401
[57] Gong, Y. et al. Highly sensitive force sensor based on optical microfiber asymmetrical Fabry-Perot interferometer. Opt. Express 22, 3578–3584 (2014). doi: 10.1364/OE.22.003578
[58] Liu, Y. et al. Strain force sensor with ultra-high sensitivity based on fiber inline Fabry-Perot micro-cavity plugged by cantilever taper. Opt. Express 25, 7797–7806 (2017). doi: 10.1364/OE.25.007797