Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Resilient yet entirely degradable gelatin-based biogels for soft robots and electronics


Biodegradable and biocompatible elastic materials for soft robotics, tissue engineering or stretchable electronics with good mechanical properties, tunability, modifiability or healing properties drive technological advance, and yet they are not durable under ambient conditions and do not combine all the attributes in a single platform. We have developed a versatile gelatin-based biogel, which is highly resilient with outstanding elastic characteristics, yet degrades fully when disposed. It self-adheres, is rapidly healable and derived entirely from natural and food-safe constituents. We merge all the favourable attributes in one material that is easy to reproduce and scalable, and has a low-cost production under ambient conditions. This biogel is a step towards durable, life-like soft robotic and electronic systems that are sustainable and closely mimic their natural antetypes.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: A resilient yet fully degradable biogel.
Fig. 2: Tunability, stability and extreme mechanics of gelatin biogels.
Fig. 3: Resilient biogels for soft actuators.
Fig. 4: Soft and degradable electronic sensor patches.

Data availability

All the data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Information. All source files and experimental data are freely and publicly available at Additional data related to this paper may be requested from the authors.


  1. 1.

    Hoornweg, D., Bhada-Tata, P. & Kennedy, C. Environment: waste production must peak this century. Nature 502, 615–617 (2013).

    Google Scholar 

  2. 2.

    Leung, A., Luksemburg, W., Wong, A. & Wong, M. Spatial distribution of polybrominated diphenyl ethers and polychlorinated dibenzo-p-dioxins and dibenzofurans in soil and combusted residue at Guiyu, an electronic waste recycling site in southeast China. Environ. Sci. Technol. 41, 2730–2737 (2007).

    CAS  Google Scholar 

  3. 3.

    Baumgartner, M. et al. in Green Materials for Electronics (eds Irimia‐Vladu, M., Glowacki, E. D., Sariciftci, N. S. & Bauer, S.) 1–53 (Wiley, 2017)

  4. 4.

    Irimia-Vladu, M. et al. Biocompatible and biodegradable materials for organic field-effect transistors. Adv. Funct. Mater. 20, 4069–4076 (2010).

    CAS  Google Scholar 

  5. 5.

    Boutry, C. et al. A stretchable and biodegradable strain and pressure sensor for orthopaedic application. Nat. Electron. 1, 314–321 (2018).

    Google Scholar 

  6. 6.

    Walker, S. et al. Using an environmentally benign and degradable elastomer in soft robotics. Int. J. Intell. Robotics Appl. 1, 124–142 (2017).

    Google Scholar 

  7. 7.

    Hwang, S. et al. A physically transient form of silicon electronics. Science 337, 1640–1644 (2012).

    CAS  Google Scholar 

  8. 8.

    Yang, C. & Suo, Z. Hydrogel ionotronics. Nat. Rev. Mater. 3, 125–142 (2018).

    CAS  Google Scholar 

  9. 9.

    Acome, E. et al. Hydraulically amplified self-healing electrostatic actuators with muscle-like performance. Science 359, 61–65 (2018).

    CAS  Google Scholar 

  10. 10.

    Someya, T. & Amagai, M. Toward a new generation of smart skins. Nat. Biotechnol. 37, 382–388 (2019).

    CAS  Google Scholar 

  11. 11.

    Li, C. H. et al. A highly stretchable autonomous self-healing elastomer. Nat. Chem. 6, 618–624 (2016).

    Google Scholar 

  12. 12.

    Cao, Y. et al. Self-healing electronic skins for aquatic environments. Nat. Electron. 2, 75–82 (2019).

    Google Scholar 

  13. 13.

    Wang, S. et al. Skin electronics from scalable fabrication of an intrinsically stretchable transistor array. Nature 555, 83–88 (2018).

    CAS  Google Scholar 

  14. 14.

    Wirthl, D. et al. Instant tough bonding of hydrogels for soft machines and electronics. Sci. Adv. 3, e1700053 (2017).

    Google Scholar 

  15. 15.

    Wang, X. et al. Food-materials-based edible supercapacitors. Adv. Mater. Technol. 1, 1600059 (2016).

    Google Scholar 

  16. 16.

    Bauer, S. & Kaltenbrunner, M. Built to disappear. ACS Nano 8, 5380–5382 (2014).

    CAS  Google Scholar 

  17. 17.

    Yang, J., Webb, A. R. & Ameer, G. A. Novel citric acid-based biodegradable elastomers for tissue engineering. Adv. Mater. 16, 511–516 (2004).

    CAS  Google Scholar 

  18. 18.

    Webb, A. R., Yang, J. & Ameer, G. A. Biodegradable polyester elastomers in tissue engineering. Expert Opin. Biol. Ther. 4, 801–812 (2004).

    CAS  Google Scholar 

  19. 19.

    Wang, Y., Ameer, G. A., Sheppard, B. J. & Langer, R. A tough biodegradable elastomer. Nat. Biotechnol. 20, 602–606 (2002).

    CAS  Google Scholar 

  20. 20.

    Cohn, D. & Salomon, A. H. Designing biodegradable multiblock PCL/PLA thermoplastic elastomers. Biomaterials 26, 2297–2305 (2005).

    CAS  Google Scholar 

  21. 21.

    Skarja, G. A. & Woodhouse, K. A. In vitro degradation and erosion of degradable, segmented polyurethanes containing an amino acid-based chain extender. J. Biomater. Sci. Polym. Ed. 12, 851–873 (2001).

    CAS  Google Scholar 

  22. 22.

    Averous, L., Moro, L., Dole, P. & Fringant, C. Properties of thermoplastic blends: starch–polycaprolactone. Polymer 41, 4157–4167 (2000).

    CAS  Google Scholar 

  23. 23.

    Zhu, C. et al. Highly stretchable HA/SA hydrogels for tissue engineering. J. Biomater. Sci. Polym. Ed. 29, 543–561 (2018).

    CAS  Google Scholar 

  24. 24.

    Shintake, J., Sonar, H., Piskarev, E., Paik, J. & Floreano, D. Soft pneumatic gelatin actuator for edible robotics. In 2017 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) 6221–6226 (IEEE, 2017).

  25. 25.

    Van Den Bulcke, A. I. et al. Structural and rheological properties of methacrylamide modified gelatin hydrogels. Biomacromolecules 1, 31–38 (2000).

    Google Scholar 

  26. 26.

    Wu, T. et al. A pH-responsive biodegradable high-strength hydrogel as potential gastric resident filler. Macromol. Mater. Eng. 303, 1800290 (2018).

    Google Scholar 

  27. 27.

    Ceseracciu, L., Heredia-Guerrero, J. A., Dante, S., Athanassiou, A. & Bayer, I. S. Robust and biodegradable elastomers based on corn starch and polydimethylsiloxane (PDMS). ACS Appl. Mater. Interfaces 7, 3742–3753 (2015).

    CAS  Google Scholar 

  28. 28.

    He, Q., Huang, Y. & Wang, S. Hofmeister effect-assisted one step fabrication of ductile and strong gelatin hydrogels. Adv. Funct. Mater. 28, 1705069 (2018).

    Google Scholar 

  29. 29.

    Qin, Z. et al. Freezing-tolerant supramolecular organohydrogel with high toughness, thermoplasticity, and healable and adhesive properties. ACS Appl. Mater. Interfaces 11, 21184–21193 (2019).

    CAS  Google Scholar 

  30. 30.

    Schrieber, R. & Gareis, H. Gelatine Handbook (Wiley, 2007).

  31. 31.

    Luo, Z. et al. Biodegradable gelatin methacryloyl microneedles for transdermal drug delivery. Adv. Healthcare Mater. 8, 1801054 (2018).

    Google Scholar 

  32. 32.

    Echave, M. et al. Enzymatic crosslinked gelatin 3D scaffolds for bone tissue engineering. Int. J. Pharm. 562, 151–161 (2019).

    CAS  Google Scholar 

  33. 33.

    Mandrycky, C. et al. 3D bioprinting for engineering complex tissues. Biotechnol. Adv. 34, 422–434 (2016).

    CAS  Google Scholar 

  34. 34.

    Kim, D., Lee, H., Kwon, S., Choi, H. & Park, S. Magnetic nano-particles retrievable biodegradable hydrogel microrobot. Sens. Actuators B 289, 65–77 (2019).

    CAS  Google Scholar 

  35. 35.

    Chambers, L., Winfield, J., Ieropoulos, I. & Rossiter, J. Biodegradable and edible gelatine actuators for use as artificial muscles. In Proc. SPIE 9056, Electroactive Polymer Actuators and Devices 90560B (SPIE, 2014).

  36. 36.

    Sardesai, A. et al. Design and characterization of edible soft robotic candy actuators. MRS Adv. 3, 3003–3009 (2018).

    CAS  Google Scholar 

  37. 37.

    Deng, Y., Zhang, Y., Lemos, B. & Ren, H. Tissue accumulation of microplastics in mice and biomarker responses suggest widespread health risks of exposure. Sci. Rep. 7, 46687 (2017).

    Google Scholar 

  38. 38.

    Feig, V., Tran, H. & Bao, Z. Biodegradable polymeric materials in degradable electronic devices. ACS Centr. Sci. 4, 337–348 (2018).

    CAS  Google Scholar 

  39. 39.

    Shimizu, S. & Matubayasi, N. Gelation: the role of sugars and polyols on gelatin and agarose. J. Phys. Chem. B 118, 13210–13216 (2014).

    CAS  Google Scholar 

  40. 40.

    Polygerinos, P. et al. Soft robotics: review of fluid‐driven intrinsically soft devices; manufacturing, sensing, control, and applications in human–robot interaction. Adv. Engin. Mater. 19, 1700016 (2017).

    Google Scholar 

  41. 41.

    Amjadi, M., Kyung, K.-U., Park, I. & Sitti, M. Stretchable, skin-mountable, and wearable strain sensors and their potential applications: a review. Adv. Funct. Mater. 26, 1678–1698 (2016).

    CAS  Google Scholar 

  42. 42.

    Krause, J., Winfield, A. & Deneubourg, J. Interactive robots in experimental biology. Trends Ecol. Evol. 26, 369–375 (2011).

    Google Scholar 

  43. 43.

    Bogue, R. Fruit picking robots: has their time come?. Ind. Robot 47, 141–145 (2010).

    Google Scholar 

  44. 44.

    Hohimer, C. J. et al. Design and field evaluation of a robotic apple harvesting system with a 3D-printed soft-robotic end-effector. Trans. ASABE 62, 405–415 (2019).

    Google Scholar 

  45. 45.

    Hartmann, F., Drack, M. & Kaltenbrunner, M. Meant to merge: fabrication of stretchy electronics for robotics. Sci. Robotics 3, eaat9091 (2018).

    Google Scholar 

  46. 46.

    Luangtana-anan, M., Nunthanid, J. & Limmatvapirat, S. Effect of molecular weight and concentration of polyethylene glycol on physicochemical properties and stability of shellac film. J. Agric. Food Chem. 58, 12934–12940 (2010).

    CAS  Google Scholar 

Download references


This work was supported by the European Research Council Starting Grant ‘GEL-SYS’ under grant agreement no. 757931, the Austrian Research Promotion Agency GmbH (FFG) within the COMET-project TextileUX under grant agreement no. 865791 and through start-up funding of the Linz Institute of Technology (LIT) ‘Soft Electronics Laboratory’ under grant no. LIT013144001SEL. M.B. received support from Borealis and the Borealis Social Scholarship, VDI and the Dr Maria Schaumayer Foundation. G.B. acknowledges financial support from the European Commission within the ‘LiNaBioFluid’ project within the scope of H2020-FETOPEN-2014-2015-RIA. We thank Ewald-Gelatine, especially T. Hilt, for material support and fruitful discussions. We dedicate this work to S. Bauer.

Author information




M.B., S.B. and M.K. conceived the research project; M.B. developed the materials with input from G.B. and S.H.; F.H., M.B. and M.D. designed the experiments; M.B., L.L., D.P., F.H. and L.R. prepared the materials; F.H., M.B., D.W., L.R., L.L., F.G., M.S. and E.B. conducted the mechanical materials characterization; M.B., R.G. and D.P. performed the BOD and dissolution tests; S.D. recorded the SEM images; G.M. and F.H. conducted the mechanical simulations and modelling; M.B., D.P. and F.H. developed and characterized the soft actuator; F.H., R.P., M.D. and T.S. developed and characterized the degradable sensor patches; R.P. and D.S. developed the flex, PCB and software; S.K. performed the bacterial growth tests; F.H., D.W. and M.D. analysed the data; M.K. gave input at all the stages; F.H., M.B., M.D., D.W. and M.K. wrote the manuscript; all the authors contributed to editing the manuscript. M.K. supervised the research.

Corresponding author

Correspondence to Martin Kaltenbrunner.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Degradation of biomaterials.

a, A bioinspired soft actuator consisting of wood, cotton-yarn, and gelatin-based biogel. b, Degradation reaction and end product of cellulose. c, Degradation and end product of gelatin. Single polypeptide strands are split by microorganisms found in waste water, gut, or soils.

Extended Data Fig. 2 Biodegradable soft robot demonstrator “Percy the Gellyfant”.

a, The manually actuated elephant trunk in its relaxed state and b, actuated u-shaped state. c, U-shaped movement allows grabbing of various objects. Scale bar, 2 cm.

Extended Data Fig. 3 Assembly of sensor skins.

Assembly process of the sensor skin consisting of degradable e-skin and reusable PCB. 1, Gels of different mechanical properties are joined by laser assisted rapid healing (LARH). 2–3, A zinc metal sheet is then applied to the gel and structured by a fiber laser. 4, After the structuring process the zinc residues are peeled off. 5, A flexible reusable PCB is mounted on the gel and soldered to the zinc foil of the e-skin. In the last fabrication step a temperature sensitive paste is placed on the gel to finalize the temperature sensor.

Extended Data Fig. 4 Biodegradable sensors characterization.

a, Stretchable meanders of zinc foil serve as conductors on biogels (G1730). b, Repeated stretching and increase of the maximum strain does not affect the conductivity of the zinc meanders. Mean resistance changes (solid line) during stretch-release cycles (data envelope) are shown. c, Those are durable for over 1000 stretching cycles, when stretched to a maximum strain of 20 %. d, Humidity sensors are realized with structured zinc foil on biogels (G2430). e, The magnitude of the impedance Z is measured as function of frequency at different climatic conditions, showing a change of two orders of magnitude. f, The sensor response is below 1 % when stretched repeatedly to a maximum strain of 10 %. g, Temperature sensors are realized with a conductive paste between two stretchable conductors on a biogel (G3030). h, The conductive pastes, fabricated on glass substrates, show a change larger than a factor of 2 over a range of 30 °C. Error bars, standard deviation for a measurement period >10 min. i, Strain sensors are designed with 5 fingers total to allow displacement of the electrodes. j, The sensor signals follow the applied strain profile linearly. Repeated cycles are tested between 20 % and 40 % strain, to account for irreversible mechanical deformation of the substrate during the first stretch-release cycle. Scale bars, 5 mm.

Extended Data Fig. 5 Adhesion tests.

a, Schematic of the 90° peel-test used to measure the debond energy between a biogel slightly pressed against diverse substrates. A 6 µm thick PET foil serves as stiff backing to prevent elongation of the peel arm, whereas a linear guiding ensures a constant angle of 90°. b, Measured debond energy for aluminum (blue), paper (purple), porcine skin (turquoise), PDMS (orange) and Ecoflex (red). c, Photographs of a biogel-porcine skin peel-sample taken during a peel-test showing the propagation of the peel-front between biogel and substrate. Mean values (solid line) and standard deviation (shadow) for n > 4 samples each. Scale bar, 1 cm.

Extended Data Fig. 6 On skin test – long time adherence.

a, Two gel discs (G1730) with a thickness of 1 mm and 2 mm and a diameter of 2 cm were applied on the skin of the upper arm with little pressure. Scale bar, 2 cm. b, The test started at 9am, c, and showed no signs of gel disintegration during 4 h of wearing. Scale bars, 1 cm. d, Even after sports activities (13 pm to 14 pm) that involved higher mechanical load and sweating, there are no signs of detachment. Scale bar, 1 cm. e, After 7 h the biogel still adheres to the skin, even at the edges of the gel. Scale bar, 1 cm. f, The gel can be removed with no visible irritations after removal. Scale bar, 2 cm. g, Rectangular stripes were applied on the skin for up to 4 days (5–12 h each day) and compared to reference samples of the same batch. Mean values (solid line) and data envelope (gray shadow) for n > 3 samples each are shown. The biogel mechanics do not change upon wearing, even after 38 h wear-time on skin, resulting in constant h, Young’s modulus (ref. A: 170 kPa ± 4 kPa, ref. B: 207 kPa ± 5 kPa), i, ultimate stress (ref. A: 830 kPa ± 60 kPa, ref. B: 1070 kPa ± 26 kPa), j, and ultimate strain (ref. A: 373 % ± 26 %, ref. B: 423 % ± 22 %). Error bars, standard deviation for a n > 3 measurements.

Extended Data Fig. 7 Pressure skin.

a–d, A weight of 20 g is applied to single pixels of the pressure skin sensor matrix. The measurement shows an impedance increase of 7–15 % compared to the initial value. Scale bar, 2 cm.

Supplementary information

Supplementary Information

Supplementary Discussion, Methods, Tables 1–3, Figs. 1–24 and Video captions 1–13.

Supplementary Video 1

Dissolution of biogel. The video shows dissolution of a disk of G1620 biogel in DI-water.

Supplementary Video 2

Dissolution of biogel foam. The video shows dissolution of a disk of G1215f biogel foam in DI-water.

Supplementary Video 3

Biodegradable encapsulation. The video shows dissolution of a disk of a G2430 biogel in DI-water in comparison to an equal disk with a biodegradable encapsulation. The initial color change of the coating is typical for shellac immersed in water. The biodegradable encapsulation significantly delays biogel dissolution also in acidic solutions (citric acid, pH 2.1). Degradation is triggered by basic solutions (Tris buffer, pH 8.1).

Supplementary Video 4

Inflation of biogels. The video shows inflation of three different biogels (G2820, G2420, and G1620). The comparison of the biogels shows that G2820 biogel allows for the largest strains.

Supplementary Video 5

Motion of the biogel actuators. The video shows u-shaped and s-shaped motion of the biogel actuators. An actuator tube made from fluorescent biogel is barely visible in relaxed state, but fully visible when actuated due to increased surface area of the biogel.

Supplementary Video 6

Biogel actuators operating underwater. Pneumatic actuators are dip-coated in cooking oil and operate in 20 °C DI-water. Actuator reaches 900 actuation cycles after 45 min of operation. Action continues over 1.5 h with more than 1500 actuation cycles before failure.

Supplementary Video 7

Lifting of objects with the s-shaped actuator. The video shows an actuator tube with a suction cup on its tip lifting objects. Vacuum is applied when an object is in contact with the suction cup and turned off when the lifting movement is over. Different sizes of objects can be lifted. Even objects that are smaller than the suction cup itself. Small dolls are equally lifted despite different weights ranging from 5.5 g to 30 g. The actuator (actuator weight ~35 g) lifts objects up to 119 g.

Supplementary Video 8

Interaction between two soft biodegradable robots. 1, In this video two biodegradable robots perform a manually actuated ball transfer. At the beginning the smaller degradable robot “Percy the Gellyfant” with inflated u-shaped trunk holds a sphere shaped object. The s-shaped actuator of the larger plywood soft robot has a suction cup attached to its front end and is also in its inflated state. 2, While Percy is still holding the table tennis ball the plywood elephant slowly deflates and approaches the round object until the suction cup completely touches it. 3, Vacuum is manually applied to the suction cup while the actuator of Percy is deflated. 4, As the actuator of Percy is deflated the plywood elephant actuator is inflated and lifts the table tennis ball. 5, The plywood elephant is then deflated and approaches the now inflated trunk of Percy. 6, When the biogel-actuator of Percy is bent to a curve, the lowered suction cup of the plywood elephant actuator places the table tennis ball back in Percys trunk. “Percy the Gellyfant” is holding an object. 1, The manually actuated u-shaped trunk is holding a cylindrical rigid object. 2, When the trunk is deflated the object is released 3, until it is dropped.

Supplementary Video 9

Pressure sensor enhanced smart soft actuator. 1, The video shows the movement of an u-shaped biogel actuator against a rigid object. On the tip of the soft actuator a pressure sensor is mounted, which is triggered when the sensor is compressed by contact to an object. The inflation and deflation is automated by a program. 2, At first the actuator passes by a screwdriver after inflation 3, until it reaches its maximum bending angle. At this point the deflation is actuated by the program and not by the sensor. 4, In the second case the biogel-actuator is again inflated by the program with the screwdriver in its trajectory. 5, The actuator approaches the object. After contact the foam sensor is compressed and initiates the deflation. 6, The soft actuator retreats from the screwdriver until it is completely deflated. 7, Via automated inflation of the actuator the pressure sensor at top of the actuator tip approaches a sharp rose thorn. 8, Contact with the sharp thorn compresses the pressure sensor without harming it and triggers retracting from the pointed obstacle. 9, The actuator retreats fully from the obstacle.

Supplementary Video 10

Autonomous soft electronic sensor skin. The video shows an electronic skin that intrinsically adheres to the human body. The e-skin sticks to the skin under shaking and twisting of the arm. Wireless communication and signal processing is placed on a flexible PCB, whereas the rest of the e-skin is biodegradable and stretchable. The impedance change is monitored during aspiration of the e-skin. Temperature sensors monitor hot objects like a cup with hot water. The e-skin is peeled off from the body after use.

Supplementary Video 11

Powder coating for reduced adhesion. The video shows biogels covered with talcum powder. 1, Powder covered biogels loose their stickiness. 2, The powder is removed from the surface by wiping it away with water. 3, With the powder removed, the biogel’s adhesion to arbitrary surfaces is restored.

Supplementary Video 12

Biogel thin film. 1, The video shows a biogel thin film (G1730) of 0.58 mm thickness, prepared with doctor blading. 2, The film is coated with talcum powder to make handling easier. 3, The thin film is reversibly highly stretchable and 4, deformable.

Supplementary Video 13

Soft pressure sensor array. The video shows a 4 ×4 pressure sensor array monitoring different loads. Weights (10 g, 20 g, 50 g) are placed on a single sensor to demonstrate its response. A 20 g weight is placed on different sensors. The position of the weight is detected throughout the whole skin.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Baumgartner, M., Hartmann, F., Drack, M. et al. Resilient yet entirely degradable gelatin-based biogels for soft robots and electronics. Nat. Mater. 19, 1102–1109 (2020).

Download citation


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing