Biomedical Microdevices

, 21:82 | Cite as

Untethered microgripper-the dexterous hand at microscale

  • Chao Yin
  • Fanan WeiEmail author
  • Ziheng Zhan
  • Jianghong Zheng
  • Ligang Yao
  • Wenguang Yang
  • Minglin Li


Untethered microgrippers that can navigate in hard-to-reach and unpredictable environments are significantly important for biomedical applications such as targeted drug delivery, micromanipulation, minimally invasive surgery and in vivo biopsy. Compared with the traditional tethered microgrippers, the wireless microgrippers, due to the exceptional characteristics such as miniaturized size, untethered actuation, dexterous and autonomous motion, are projected to be promising microtools in various future applications. In this review, we categorize the untethered microgrippers into five major classes, i.e. microgrippers responsive to thermal, microgrippers actuated by magnetic fields, microgrippers responsive to chemicals, light-driven microgrippers and hybrid actuated microgrippers. Firstly, the actuation mechanisms of these microgrippers are introduced. The challenges faced by these microgrippers are also covered in this part. With that, the fabrication methods of these microgrippers are summarized. Subsequently, the applications of microgrippers are presented. Additionally, we conduct a comparison among different actuation mechanisms to explore the advantages and potential challenges of various types of microgrippers. In the end of this review, conclusions and outlook of the development and potential applications of the microgrippers are discussed.


Untethered Microgripper Stimuli-responsive Biomedicine 



This work is financially supported by the National Science Foundation of China (No.61803088), and also partially supported by the Natural Science Foundation of Fujian Province, China (No. 2017 J01748), the Open Project Programs from both the State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences (Grant No: 2017-O02) and the State Key Laboratory of Photocatalysis on Energy and Environment. The author would also like to thank the funding from Fuzhou University (Grant No. SKLPEE-KF201718), and Fuzhou University Testing Fund of precious apparatus (No. 2018 T016).


  1. E.M. Ahmed, Hydrogel: Preparation, characterization, and applications: A review. J. Adv. Res. 6(2), 105–121 (2015)CrossRefGoogle Scholar
  2. F.M. Andreopoulos, E.J. Beckman, A.J. Russell, Light-induced tailoring of peg-hydrogel properties. Biomaterials 19(15), 1343–1352 (1998)CrossRefGoogle Scholar
  3. N. Bassik, B.T. Abebe, K.E. Laflin, et al., Photolithographically patterned smart hydrogel based bilayer actuators. Polymer 51(26), 6093–6098 (2010a)CrossRefGoogle Scholar
  4. N. Bassik, A. Brafman, A.M. Zarafshar, et al., Enzymatically triggered actuation of miniaturized tools. J. Am. Chem. Soc. 132(46), 16314–16317 (2010b)CrossRefGoogle Scholar
  5. T. Billiet, M. Vandenhaute, J. Schelfhout, et al., A review of trends and limitations in hydrogel-rapid prototyping for tissue engineering. Biomaterials 33(26), 6020–6041 (2012)CrossRefGoogle Scholar
  6. S. Bragança, E. Costa, I. Castellucci, et al. ‘A brief overview of the use of collaborative robots in industry 4.0: Human role and safety’, in Arezes, P.M., Baptista, J.S., Barroso, M.P., et al. (Eds.): ‘Occupational and environmental safety and health’ (Springer International Publishing), 641–650 (2019)Google Scholar
  7. J.C. Breger, C. Yoon, R. Xiao, et al., Self-folding thermo-magnetically responsive soft microgrippers. ACS Appl. Mater. Interfaces 7(5), 3398–3405 (2015)CrossRefGoogle Scholar
  8. J. Cecil *, D. Vasquez, D. Powell, A review of gripping and manipulation techniques for micro-assembly applications. Int J Prod Res 43(4), 819–828 (2007)zbMATHCrossRefGoogle Scholar
  9. J. Cecil, D. Powell, D. Vasquez, Assembly and manipulation of micro devices—a state of the art survey. Robot. Comput. Integr. Manuf. 23(5), 580–588 (2007)CrossRefGoogle Scholar
  10. X. Cheng, L. Jay Guo, A combined-nanoimprint-and-photolithography patterning technique. Microelectron. Eng. 71(3–4), 277–282 (2004)CrossRefGoogle Scholar
  11. S.W. Choi, Y.C. Yeh, Y. Zhang, et al., Uniform beads with controllable pore sizes for biomedical applications. Small 6(14), 1492–1498 (2010)CrossRefGoogle Scholar
  12. A. Choi, E. Gultepe, D.H. Gracias, ‘Pneumatic delivery of untethered microgrippers for minimally invasive biopsy’, in Editor (Ed.)^(Eds.): ‘Book Pneumatic delivery of untethered microgrippers for minimally invasive biopsy’, 857–860 (2017)Google Scholar
  13. S.E. Chung, X. Dong, M. Sitti, Three-dimensional heterogeneous assembly of coded microgels using an untethered mobile microgripper. Lab Chip 15(7), 1667–1676 (2015)CrossRefGoogle Scholar
  14. D. Conti, S. Di Nuovo, S. Buono, et al., Robots in education and care of children with developmental disabilities: A study on acceptance by experienced and future professionals. Int. J. Soc. Robot. 9(1), 51–62 (2016)CrossRefGoogle Scholar
  15. C. Danielson, A. Mehrnezhad, A. YekrangSafakar, et al., Fabrication and characterization of self-folding thermoplastic sheets using unbalanced thermal shrinkage. Soft Matter 13(23), 4224–4230 (2017)CrossRefGoogle Scholar
  16. D. de Lanauze, O. Felfoul, J.-P. Turcot, et al., Three-dimensional remote aggregation and steering of magnetotactic bacteria microrobots for drug delivery applications. 33(3), 359–374 (2014)Google Scholar
  17. E. Diller, M. Sitti, Three-dimensional programmable assembly by untethered magnetic robotic micro-grippers. Adv. Funct. Mater. 24(28), 4397–4404 (2014)CrossRefGoogle Scholar
  18. E. Diller, N. Zhang, M. Sitti, Modular micro-robotic assembly through magnetic actuation and thermal bonding. Journal of Micro-Bio Robotics 8(3), 121–131 (2013)CrossRefGoogle Scholar
  19. A.M. Flynn, L.S. Tavrow, S.F. Bart, et al., Piezoelectric micromotors for microrobots. J. Microelectromech. Syst. 1(1), 44–51 (1992)CrossRefGoogle Scholar
  20. S. Fusco, M.S. Sakar, S. Kennedy, et al., An integrated microrobotic platform for on-demand, targeted therapeutic interventions. Adv. Mater. 26(6), 952–957 (2014)CrossRefGoogle Scholar
  21. T.R. Ger, H.T. Huang, W.Y. Chen, et al., Magnetically-controllable zigzag structures as cell microgripper. Lab Chip 13(12), 2364–2369 (2013)CrossRefGoogle Scholar
  22. J. Giltinan, E. Diller, M. Sitti, Programmable assembly of heterogeneous microparts by an untethered mobile capillary microgripper. Lab Chip 16(22), 4445–4457 (2016)CrossRefGoogle Scholar
  23. G. Go, H. Choi, S. Jeong, et al., Selective microrobot control using a thermally responsive microclamper for microparticle manipulation. Smart Mater Struct 25(3), 035004 (2016)CrossRefGoogle Scholar
  24. G. Go, V.D. Nguyen, Z. Jin, et al., A thermo-electromagnetically actuated microrobot for the targeted transport of therapeutic agents. Int. J. Control. Autom. Syst. 16(3), 1341–1354 (2018)CrossRefGoogle Scholar
  25. M. Grossard, M. Boukallel, N. Chaillet, et al., Modeling and robust control strategy for a control-optimized piezoelectric microgripper. IEEE/ASME Transactions on Mechatronics 16(4), 674–683 (2011)CrossRefGoogle Scholar
  26. Z. Gu, T.T. Dang, M. Ma, et al., Glucose-responsive microgels integrated with enzyme nanocapsules for closed-loop insulin delivery. ACS Nano 7(8), 6758–6766 (2013)CrossRefGoogle Scholar
  27. E. Gultepe, J.S. Randhawa, S. Kadam, et al., Biopsy with thermally-responsive untethered microtools. Adv. Mater. 25(4), 514–519 (2013)CrossRefGoogle Scholar
  28. M. Hagiwara, T. Kawahara, Y. Yamanishi, et al., On-chip magnetically actuated robot with ultrasonic vibration for single cell manipulations. Lab Chip 11(12), 2049–2054 (2011)CrossRefGoogle Scholar
  29. M.S. Hahn, L.J. Taite, J.J. Moon, et al., Photolithographic patterning of polyethylene glycol hydrogels. Biomaterials 27(12), 2519–2524 (2006)CrossRefGoogle Scholar
  30. J. Han, J. Zhen, V. Du Nguyen, et al., Hybrid-actuating macrophage-based microrobots for active cancer therapy. Sci. Rep. 6, 28717 (2016)CrossRefGoogle Scholar
  31. E. Heitzer, P. Ulz, J.B. Geigl, Circulating tumor DNA as a liquid biopsy for cancer. Clin. Chem. 61(1), 112–123 (2015)CrossRefGoogle Scholar
  32. W. Hu, K.S. Ishii, A.T. Ohta ‘Micro-assembly using optically controlled bubble microrobots’, Appl. Phys. Lett., 99, (9) (2011)CrossRefGoogle Scholar
  33. W. Hu, Q. Fan, A.T. Ohta, Interactive actuation of multiple opto-thermocapillary flow-addressed bubble microrobots. Robotics and Biomimetics 1(1), 14 (2014)CrossRefGoogle Scholar
  34. N. Hu, L. Wang, W. Zhai, et al. ‘Magnetically actuated rolling of star-shaped hydrogel microswimmer’, Macromol Chem Phys, 219, (5) (2018)CrossRefGoogle Scholar
  35. C. Huang, J.-a. Lv, X. Tian, et al. ‘A remotely driven and controlled micro-gripper fabricated from light-induced deformation smart material’, Smart Materials and Structures, 25, (9) (2016)CrossRefGoogle Scholar
  36. A. Ichikawa, S. Sakuma, M. Sugita, et al. ‘On-chip enucleation of an oocyte by untethered microrobots’, Journal of Micromechanics and Microengineering, 24, (9) (2014)CrossRefGoogle Scholar
  37. T. Ikeda, O. Tsutsumi ‘Optical Switching and Image Storage by Means of Azobenzene Liquid-Crystal Films’, 268, (5219), pp. 1873-1875 (1995)Google Scholar
  38. L. Ionov, Hydrogel-based actuators: Possibilities and limitations. Mater. Today 17(10), 494–503 (2014)CrossRefGoogle Scholar
  39. M. Johnson, Y. Chen, S. Hovet, et al., Fabricating biomedical origami: A state-of-the-art review. Int. J. Comput. Assist. Radiol. Surg. 12(11), 2023–2032 (2017)CrossRefGoogle Scholar
  40. M. Kanduc, A. Schlaich, E. Schneck, et al., Water-mediated interactions between hydrophilic and hydrophobic surfaces. Langmuir 32(35), 8767–8782 (2016)CrossRefGoogle Scholar
  41. C.-J. Kim, A.P. Pisano, R.S. Muller, et al., Polysilicon microgripper. Sensors Actuators A Phys. 33(3), 221–227 (1992)CrossRefGoogle Scholar
  42. J. Kim, S.E. Chung, S.-E. Choi, et al., Programming magnetic anisotropy in polymeric microactuators. Nat. Mater. 10, 747 (2011)CrossRefGoogle Scholar
  43. S. Kim, F. Qiu, S. Kim, et al., Fabrication and characterization of magnetic microrobots for three-dimensional cell culture and targeted transportation. Adv. Mater. 25(41), 5863–5868 (2013)CrossRefGoogle Scholar
  44. M. Kiristi, V.V. Singh, B. Esteban-Fernández de Ávila, et al., Lysozyme-based antibacterial nanomotors. ACS Nano 9(9), 9252–9259 (2015)CrossRefGoogle Scholar
  45. K. Kobayashi, C. Yoon, S.H. Oh, et al. ‘Biodegradable Thermomagnetically Responsive Soft Untethered Grippers’, ACS Appl Mater Interfaces, 11 (1), 151-159 (2019)CrossRefGoogle Scholar
  46. J.-C. Kuo, H.-W. Huang, S.-W. Tung, et al., A hydrogel-based intravascular microgripper manipulated using magnetic fields. Sensors Actuators A Phys. 211, 121–130 (2014)CrossRefGoogle Scholar
  47. J.H. Kyung, B.G. Ko, Y.H. Ha, et al., Design of a microgripper for micromanipulation of microcomponents using sma wires and flexible hinges. Sensors Actuators A Phys. 141(1), 144–150 (2008)CrossRefGoogle Scholar
  48. A.P. Lee, D.R. Ciarlo, P.A. Krulevitch, et al., A practical microgripper by fine alignment, eutectic bonding and sma actuation. Sensors Actuators A Phys. 54(1), 755–759 (1996)CrossRefGoogle Scholar
  49. T.G. Leong, C.L. Randall, B.R. Benson, et al., Tetherless thermobiochemically actuated microgrippers. Proc. Natl. Acad. Sci. 106(3), 703–708 (2009)CrossRefGoogle Scholar
  50. C. Li, F. Cheng, J.-A. Lv, et al. ‘Light-controlled quick switch of adhesion on a micro-arrayed liquid crystal polymer superhydrophobic film’, Soft Matter, 8, (14) (2012)CrossRefGoogle Scholar
  51. T. Li, J. Li, H. Zhang, et al., Magnetically propelled fish-like nanoswimmers. Small 12(44), 6098–6105 (2016a)CrossRefGoogle Scholar
  52. H. Li, G. Go, S.Y. Ko, et al. ‘Magnetic actuated ph-responsive hydrogel-based soft micro-robot for targeted drug delivery’, Smart Materials and Structures, 25, (2) (2016b)CrossRefGoogle Scholar
  53. T. Li, J. Li, K.I. Morozov, et al., Highly efficient freestyle magnetic nanoswimmer. Nano Lett. 17(8), 5092–5098 (2017a)CrossRefGoogle Scholar
  54. T. Li, X. Chang, Z. Wu, et al., Autonomous collision-free navigation of microvehicles in complex and dynamically changing environments. ACS Nano 11(9), 9268–9275 (2017b)CrossRefGoogle Scholar
  55. T. Li, A. Zhang, G. Shao, et al. ‘Janus microdimer surface walkers propelled by oscillating magnetic fields’, Adv Funct Mater, 28, (25) (2018a)CrossRefGoogle Scholar
  56. S. Li, Q. Jiang, S. Liu, et al., A DNA nanorobot functions as a cancer therapeutic in response to a molecular trigger in vivo. Nat. Biotechnol. 36(3), 258–264 (2018b)CrossRefGoogle Scholar
  57. X. Liang, Y. Sun, H. Ren, A flexible fabrication approach toward the shape engineering of microscale soft pneumatic actuators. IEEE Robotics and Automation Letters 2(1), 165–170 (2017)CrossRefGoogle Scholar
  58. Z. Lu, X. Zhang, C. Leung, et al., Robotic icsi (intracytoplasmic sperm injection). IEEE Trans. Biomed. Eng. 58(7), 2102–2108 (2011)CrossRefGoogle Scholar
  59. H.-L. Ma, Q. Jiang, S. Han, et al. ‘Multicellular tumor spheroids as an in vivo–like tumor model for three-dimensional imaging of chemotherapeutic and nano material cellular penetration’, Molecular Imaging, 11, (6) (2012)CrossRefGoogle Scholar
  60. J.D. Madden, Mobile robots: Motor challenges and materials solutions. Science 318(5853), 1094 (2007)CrossRefGoogle Scholar
  61. K. Malachowski, J. Breger, H.R. Kwag, et al., Stimuli-responsive theragrippers for chemomechanical controlled release. Angew Chem Int Ed Engl 53(31), 8045–8049 (2014)CrossRefGoogle Scholar
  62. B.F. Malle, Integrating robot ethics and machine morality: The study and design of moral competence in robots. Ethics Inf. Technol. 18(4), 243–256 (2016)CrossRefGoogle Scholar
  63. S. Martel, ‘Combining pulsed and dc gradients in a clinical mri-based microrobotic platform to guide therapeutic magnetic agents in the vascular network’, Int J Adv Robot Syst, 10, (1) (2013)CrossRefGoogle Scholar
  64. S. Martel, M. Mohammadi, O. Felfoul, et al., Flagellated magnetotactic bacteria as controlled mri-trackable propulsion and steering systems for medical nanorobots operating in the human microvasculature. 28(4), 571–582 (2009)Google Scholar
  65. D. Martella, S. Nocentini, D. Nuzhdin, et al. ‘Photonic microhand with autonomous action’, Adv Mater, 29, (42) (2017)CrossRefGoogle Scholar
  66. D. Morales, E. Palleau, M.D. Dickey, et al., Electro-actuated hydrogel walkers with dual responsive legs. Soft Matter 10(9), 1337–1348 (2014)CrossRefGoogle Scholar
  67. M.L. O'Grady, P.L. Kuo, K.K. Parker, Optimization of electroactive hydrogel actuators. ACS Appl. Mater. Interfaces 2(2), 343–346 (2010)CrossRefGoogle Scholar
  68. C. Ohm, M. Brehmer, R. Zentel, Liquid crystalline elastomers as actuators and sensors. Adv. Mater. 22(31), 3366–3387 (2010)CrossRefGoogle Scholar
  69. F. Ongaro, S. Scheggi, A. Ghosh, et al., Design, characterization and control of thermally-responsive and magnetically-actuated micro-grippers at the air-water interface. PLoS One 12(12), e0187441 (2017a)CrossRefGoogle Scholar
  70. F. Ongaro, S. Scheggi, C. Yoon, et al., Autonomous planning and control of soft untethered grippers in unstructured environments. J Microbio Robot 12(1), 45–52 (2017b)CrossRefGoogle Scholar
  71. J. Orozco, D. Vilela, G. Valdes-Ramirez, et al., Efficient biocatalytic degradation of pollutants by enzyme-releasing self-propelled motors. Chemistry 20(10), 2866–2871 (2014)CrossRefGoogle Scholar
  72. M. Pal, N. Somalwar, A. Singh, et al., Maneuverability of magnetic nanomotors inside living cells. Adv Mater 30(22), e1800429 (2018)CrossRefGoogle Scholar
  73. S.J. Park, S.H. Park, S. Cho, et al., New paradigm for tumor theranostic methodology using bacteria-based microrobot. Sci. Rep. 3, 3394 (2013)CrossRefGoogle Scholar
  74. M. Power, A.J. Thompson, S. Anastasova, et al., A monolithic force-sensitive 3d microgripper fabricated on the tip of an optical fiber using 2-photon polymerization. Small 14(16), e1703964 (2018)CrossRefGoogle Scholar
  75. S. Rahimi, E.H. Sarraf, G.K. Wong, et al., Implantable drug delivery device using frequency-controlled wireless hydrogel microvalves. Biomed. Microdevices 13(2), 267–277 (2011)CrossRefGoogle Scholar
  76. J.S. Randhawa, T.G. Leong, N. Bassik, et al., Pick-and-place using chemically actuated microgrippers. J. Am. Chem. Soc. 130(51), 17238–17239 (2008)CrossRefGoogle Scholar
  77. J.S. Randhawa, M.D. Keung, P. Tyagi, et al., Reversible actuation of microstructures by surface-chemical modification of thin-film bilayers. Adv. Mater. 22(3), 407–410 (2010)CrossRefGoogle Scholar
  78. A. Richter, G. Paschew, S. Klatt, et al. ‘Review on hydrogel-based ph sensors and microsensors’, Sensors, 8, (1) (2008)CrossRefGoogle Scholar
  79. O.G. Schmidt, K. Eberl, Thin solid films roll up into nanotubes. Nature 410, 168 (2001)CrossRefGoogle Scholar
  80. M.M. Siddiqui, S. Rais-Bahrami, B. Turkbey, et al., Comparison of mr/ultrasound fusion-guided biopsy with ultrasound-guided biopsy for the diagnosis of prostate cancer. JAMA 313(4), 390–397 (2015)CrossRefGoogle Scholar
  81. A.A. Solovev, S. Sanchez, M. Pumera, et al., Magnetic control of tubular catalytic microbots for the transport, assembly, and delivery of micro-objects. Adv. Funct. Mater. 20(15), 2430–2435 (2010)CrossRefGoogle Scholar
  82. G. Stoychev, N. Puretskiy, L. Ionov, ‘Self-folding all-polymer thermoresponsive microcapsules’, Soft Matter, 7, (7) (2011)CrossRefGoogle Scholar
  83. F. Tendick, S.S. Sastry, R.S. Fearing, et al., Applications of micromechatronics in minimally invasive surgery. IEEE/ASME Transactions on Mechatronics 3(1), 34–42 (1998)CrossRefGoogle Scholar
  84. M. Verotti, A. Dochshanov, N.P. Belfiore, ‘A comprehensive survey on microgrippers design: Mechanical structure’, J Mech Des, 139, (6) (2017)CrossRefGoogle Scholar
  85. E. Wang, M.S. Desai, S.W. Lee, Light-controlled graphene-elastin composite hydrogel actuators. Nano Lett. 13(6), 2826–2830 (2013)CrossRefGoogle Scholar
  86. H. Wang, B. Khezri, M. Pumera, Catalytic DNA-functionalized self-propelled micromachines for environmental remediation. Chem 1(3), 473–481 (2016)CrossRefGoogle Scholar
  87. T.J. White, D.J. Broer, Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. Nat. Mater. 14, 1087 (2015)CrossRefGoogle Scholar
  88. Z. Wu, B. Esteban-Fernandez de Avila, A. Martin, et al., Rbc micromotors carrying multiple cargos towards potential theranostic applications. Nanoscale 7(32), 13680–13686 (2015)CrossRefGoogle Scholar
  89. W. Xi, A.A. Solovev, A.N. Ananth, et al., Rolled-up magnetic microdrillers: Towards remotely controlled minimally invasive surgery. Nanoscale 5(4), 1294–1297 (2013)CrossRefGoogle Scholar
  90. H. Xu, M. Medina-Sanchez, V. Magdanz, et al., Sperm-hybrid micromotor for targeted drug delivery. ACS Nano 12(1), 327–337 (2018)CrossRefGoogle Scholar
  91. S. Yang, Q. Xu, A review on actuation and sensing techniques for mems-based microgrippers. Journal of Micro-Bio Robotics 13(1–4), 1–14 (2017)CrossRefGoogle Scholar
  92. J. Yang, C. Zhang, X. Wang, et al., Development of micro- and nanorobotics: A review. SCIENCE CHINA Technol. Sci. 62(1), 1–20 (2018)CrossRefGoogle Scholar
  93. S. Yim, E. Gultepe, D.H. Gracias, et al., Biopsy using a magnetic capsule endoscope carrying, releasing, and retrieving untethered microgrippers. IEEE Trans. Biomed. Eng. 61(2), 513–521 (2014)CrossRefGoogle Scholar
  94. C. Yoon, R. Xiao, J. Park, et al. ‘Functional stimuli responsive hydrogel devices by self-folding’, Smart Mater Struct, 23, (9) (2014)CrossRefGoogle Scholar
  95. Y. Yu, M. Nakano, T. Ikeda, Directed bending of a polymer film by light. Nature 425(6954), 145–145 (2003)CrossRefGoogle Scholar
  96. J. Yu, B. Wang, X. Du, et al., Ultra-extensible ribbon-like magnetic microswarm. Nat Commun 9(1), 3260 (2018)CrossRefGoogle Scholar
  97. J. Zhang, E. Diller, ‘Tetherless mobile micrograsping using a magnetic elastic composite material’, Smart Mater Struct, 25, (11) (2016)CrossRefGoogle Scholar
  98. J. Zhang, O. Onaizah, K. Middleton, et al., Reliable grasping of three-dimensional untethered mobile magnetic microgripper for autonomous pick-and-place. IEEE Robotics and Automation Letters 2(2), 835–840 (2017)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.School of Mechanical Engineering and AutomationFuzhou UniversityFuzhouChina
  2. 2.State Key Laboratory of Robotics, Shenyang Institute of AutomationChinese Academy of SciencesShenyangChina
  3. 3.School of Electromechanical and Automotive EngineeringYantai UniversityYantaiChina

Personalised recommendations