3 ms·

It's difficult to couple hard and soft components. The difference in stiffness creates stress concentrations that lead to the interface failing. This is also wh

by gene-h 8y ago

It's difficult to couple hard and soft components. The difference in stiffness creates stress concentrations that lead to the interface failing. This is also why rubber pads on laptops always tend to fall off. Creating a gradual change in stiffness is possible, but is difficult to accomplish. There is also interest in soft robotics research to make robots entirely soft. The reasons for doing this is that a soft robot can potentially not injure a human being if it's entirely soft and to make robots that can squeeze through holes. I'd also like to argue that much of the interest in soft robotics today is stems from DARPA's Chemical Robots from 2008[0], a big goal of which was to make robots capable of squeezing through holes, which has obvious military applications. [0]https://techcrunch.com/2008/07/01/darpa-throws-33m-at-biomimetic-chembots/ https://techcrunch.com/2008/07/01/darpa-throws-33m-at-biomim...

londons_explore 8y ago
It's notable that hard and soft things in nature are bonded together through progressively stiffer bonds. Eg. Muscle to tendon to cartilage to bone. Each of those transitions is more of a 'fade' than a sudden edge. Doing that with a 3d printer is hard
- gene-h 8y ago
  It depends on the 3d printer. Object Connex 3d printers, which use an inkjet to spray resins of different stiffness can do this. A number of different stiffnesses are possible by mixing different hard and soft resins together. Really the only limitations to how sudden the changes in stiffness are with this approach is that the manufacturer restricts you to only nine different material types. Oh and the manufacturer won't work with you ever again if you hack the printer drivers. This approach has been used to make soft robots with graded stiffness too[0]. [0]https://gmwgroup.harvard.edu/pubs/pdf/1255.pdf https://gmwgroup.harvard.edu/pubs/pdf/1255.pdf
- benmowa 8y ago
  you cant just mix the two materials gradually like the mystery flavors? https://youtu.be/xUpGTvPrCG8?t=203 https://youtu.be/xUpGTvPrCG8?t=203

by gene-h 8y ago

londons_explore 8y ago

It's notable that hard and soft things in nature are bonded together through progressively stiffer bonds. Eg. Muscle to tendon to cartilage to bone. Each of those transitions is more of a 'fade' than a sudden edge. Doing that with a 3d printer is hard

gene-h 8y ago
It depends on the 3d printer. Object Connex 3d printers, which use an inkjet to spray resins of different stiffness can do this. A number of different stiffnesses are possible by mixing different hard and soft resins together. Really the only limitations to how sudden the changes in stiffness are with this approach is that the manufacturer restricts you to only nine different material types. Oh and the manufacturer won't work with you ever again if you hack the printer drivers. This approach has been used to make soft robots with graded stiffness too[0]. [0]https://gmwgroup.harvard.edu/pubs/pdf/1255.pdf https://gmwgroup.harvard.edu/pubs/pdf/1255.pdf
benmowa 8y ago
you cant just mix the two materials gradually like the mystery flavors? https://youtu.be/xUpGTvPrCG8?t=203 https://youtu.be/xUpGTvPrCG8?t=203