Once this decision has been made, we’ll update our existing CAD to both reflect the new cavity shape (if applicable) as well as the thicker bottom of the part that we discussed in previous updates. These modifications should be fairly quick to implement and send to the 3D printer as the current CAD is modularly designed!

We’ve also begun working on code for the showcase display of our design. The concept behind our display is that a computer vision program would see the user’s hand, decide whether it was open or closed, and activate the pump accordingly such that our model would mirror the position of the user’s hand.

The computer vision portion of the code is completed:

We are currently working on connecting the pumps to be controlled by a raspberry pi pico. The last step will be connecting the two portions of code together!

This is the new hinge model, which we expect to be printed in ABS and can be attached to the finger by means of a strap.

Casting the ABS hinge in silicone was a success; both parts came out cleanly, and are ready to be bonded this week! Below are photos are the silicone parts:

As for the finger mold, casting this was less successful. From the get go, the mold print didn’t seem the cleanest or most exact, and we were worried how the lack of precision would effect the small gaps between our hollow channels. Additionally, while pulling the silicone part from the mold, we noticed that the bottom of the part was incredibly stringy/shredded, much more so than the hinge part. In addition to this, there were many air pockets in the part, which will definitely impact the functionality of the part:

We attempted to bond these parts after cleaning up the silicone strings, but the unintentional air pockets impaired the shape too much for them to adequately be flush against one another.

When casting, we made sure to apply silicone to both the top and bottom parts as Garth recommended, to avoid issues. We believe this issue is a result of the print quality; it appeared that silicone sank into the 3D printed part, causing air bubbles.

While designing the new part, one of the biggest design changes we made was modifying the ratio of silicone thickness above and below the hollow channels. Originally, they were roughly the same thickness, but the new design made the bottom 75% thicker than the top. We realized that we could roughly test this innovation by adding a solid piece of silicone to the bottom of our original part from a few weeks ago, making the bottom thicker.

Using a random, simple mold we found at the silicone casting tables, we cast and bonded this piece to the bottom:

This original part has a hole where the tube meets the silicone and, unfortunately after trying to patch it multiple times, we were not able to get it to fully work as intend. That being said, we were able to see a bit of bend when we quickly injected air into the part, giving us some validation to support this design change! The video to this test is linked here

We’ve re-casted our original part design along with the bottom “extension” so that we can hopefully retry this test without leakage to gain stronger validation on our idea.

1. A piece of activated wire is able to bend both a piece of silicone and a piece of deactivated wire
2. An activated nitinol wire will not tear through or otherwise damage the silicone part

Our project is an actuating silicone hand. Each finger’s large movements will be powered via pneumatic pumps, and current-driven nitinol wire will fine-tune these movements. The finger will be cast in two parts out of silicone and fused together; afterwards, trained nitinol will be strategically guided into the cured silicone, with wire leads attached to a current supply coming out of the base (see sketches below).

Updated Sketches

First Experiment Summary

Our first experiment will be broken down into two parts:

Part 1 – Silicone Casting

We were able to “successfully” cast our part in silicone, however, the 3D print failed about ⅔ of the way through. We hope that our first iteration will allow us to test the design in terms of functionality, however, we still want to test our full design.

Part 2 – SMA Training

The second half of our first experiment involves us both getting used to working with and training Shape Memory Alloys (SMA). We have samples, and want to practice heating them up to remember bent shapes, as well as use this trial and error to choose a specific gauge to embed in our part.

Reference

M. N. Golchin, A. Hadi and B. Tarvirdizadeh. Development of A New Soft Robotic Module Using Compressed Air and Shape Memory Alloys. In 2021 9th RSI International Conference on Robotics and Mechatronics (ICRoM), Tehran, Iran, Islamic Republic of. 517-522. https://doi.org/10.1109/ICRoM54204.2021.9663519

Here are some graphics of the silicone part we designed:

Here is the link to a Google Drive folder containing a CAD file for each of the four 3D printed mold parts, as well as a part file for our silicone finger.

https://drive.google.com/file/d/1RhHOT0v30i0zLhumngqdH4z_Mqq6vDU_/view?usp=share_link

Intention of the work:

The intention of this work is to bring attention to the climate crisis, specifically criticizing the lack of responsiveness that many people have. Within any of our lifetimes, millions of acres of land will be underwater, including parts of New York City and dozens of other major cities. The piece is meant to mark how, eventually, we may be floating on loungers atop buoys in areas that are currently okay – just as lax as we have been as this crisis progresses.

Alternative expression:

Personally, I resonate more with kinetic and/or interactive works of art. This piece is strong and makes an obvious, but nevertheless, powerful statement, but I would love to deploy soft technologies in order to make the piece dynamic. One potential concept would be initially having the lawnchair on normal “land” (like the background of the public installations) and slowly submerging the land, revealing the buoys, and adding rhythmic motion to the piece.

Technical Paper

I found a technical paper which explores a new design of fluid-inflatable actuators. It discusses how, often, the applications of fluid-filled actuators are limited due to the time it takes to actually fill them because of various properties of liquids. The new design(s) proposed in the paper have two distinct configurations, rather than a continuous slow inflation. This idea could be applied to the design in order to make the cycle of the piece more instantly repeatable, as well as provide a place for the water to be held before the chair is submerged.

Sources

Gorissen B, Melancon D, Vasios N, Torbati M, Bertoldi K. Inflatable soft jumper inspired by shell snapping. Sci Robot. 2020 May 20;5(42):eabb1967. doi: 10.1126/scirobotics.abb1967. PMID: 33022625.

Jenny Kendler. Lounging Through the Flood. URL: https://jennykendler.com/section/483111-Lounging%20Through%20the%20Flood.html (visited on 2023-02-5).

Interest 2: Semi-“Conscious” Kinetic Sculptures

Development of A New Soft Robotic Module Using Compressed Air and Shape Memory Alloys

M. N. Golchin, A. Hadi and B. Tarvirdizadeh. Development of A New Soft Robotic Module Using Compressed Air and Shape Memory Alloys. In 2021 9th RSI International Conference on Robotics and Mechatronics (ICRoM), Tehran, Iran, Islamic Republic of. 517-522. https://doi.org/10.1109/ICRoM54204.2021.9663519

Conference: International Conference on Robotics and Mechatronics (ICRoM)

Conference Guidelines Link

Peer Review

1. Do you have any conflict of interest in reviewing this paper?

No. I do not have a conflict of interest with this paper or its authors.

2. Expertise. Provide your expertise in the topics area of this.

2 – Passing knowledge.

3. Summary. Please summarize what you believe are the paper’s main contributions to the field of soft robotics.

This paper discusses the design and deployment of a robotic module device utilizing both pneumatic and SMA actuators. The design stems from pneumatic actuators commonly seen in the field of soft robotics, and attempts to improve upon this design by integrating SMA actuators — a technology specifically popular within the medical robotics field — with the purpose of both increasing the device’s degrees of freedom, as well as improving the device’s accuracy when moving.

4. Strength and weaknesses. What are the main strengths and weaknesses of this work? Does the paper have strengths in originality and novelty?

Strengths: In terms of results, this paper definitely feels strong. Based on the paper’s introduction, the premise of combining these two specific actuation methods is relatively untouched in the field of soft robotics, and the results this paper boasts could have large implications on the field, especially with regard to medical robots. The conclusion and results are well-written and clear.

Weaknesses: The paper was not the most well-written, especially in the less technical portions such as the introduction. Additionally, a large amount of the experiment itself felt very hand-wavy; specifically large portions of the design were skipped over. One specific reference appears to have informed many design decisions, however, this reference is not discussed in the paper and it is not clear how the results of that paper and the goals of this one interact. The testing procedure itself was also not very well documented as figures for PSI, voltages, and control algorithms were not discussed.

5. Soundness. Are the ideas, algorithms, results, or studies technologically/methodologically sound?

The ideas behind this experiment and ensuing results are technologically sound. Many methods and procedures deployed were not detailed, so it is harder to say whether or not it is methodologically sound, but there were no immediately apparent red flags.

6. Related Work. Does the paper adequately describe related and prior work?

No, this paper cites references multiple times but rarely makes clear what information was taken from it. It also goes into very little detail about the paper which appears to have heavily informed design decisions, saying “Based on the analysis of actuator cross-sectional shapes” without specifying what analysis they’re referring to. Much of the background information in the introduction is poorly written, vague, and generically listed.

7. Presentation. Is the paper well-organized, well-written, and clearly presented?

The paper is well-organized. I would not say that it is well-written as it lacks content in many sections, as well as has some poorly written and confusing parts. Only some parts of the paper are clearly presented, like the results discussion, but others are ambiguous and not organized in a digestible way, such as the design section.

8. Suggestions. Do you have suggestions for improving this paper?

Yes. This paper would be greatly improved by adding a more comprehensive discussion of its references, especially those which directly informed decisions made during the design and testing processes. It should also elaborate on the testing process, and including better-labeled diagrams and any additional graphs/charts which would help better communicate their findings. Overall, it could also benefit from being edited for conventions.

9. Comments to Committee. Does this paper have enough originality and importance to merit publication? Is the paper relevant to the field?

I believe that the findings of this paper are original and important to the field of soft robotics, however, ultimately, I believe that the results are muddled by the poorly written nature of the paper. I believe that this paper should not be published as is, but, if heavily edited/partially rewritten, would be relevant and important enough to the field to warrant acceptance.

10. Overall Rating. Provide your overall rating of the paper.

2 or 3 – I definitely would not argue for this paper to be published, however, I’m hovering between indifferent and inclined to argue against it. I believe that, with heavy rewriting, it should be accepted but not as it stands currently.

Mineta, T., Mitsui, T., Watanabe, Y., Kobayashi, S., Haga, Y., and Esashi, M.. An Active Guide Wire With Shape Memory Alloy Bending Actuator Fabricated by Room Temperature Process. Sens. Actuators, A, 97–98(1):632–637, 2002. https://doi.org/10.1016/S0924-4247(02)00021-3

Related Paper 1: Development of A New Soft Robotic Module Using Compressed Air and Shape Memory Alloys

M. N. Golchin, A. Hadi and B. Tarvirdizadeh. Development of A New Soft Robotic Module Using Compressed Air and Shape Memory Alloys. In 2021 9th RSI International Conference on Robotics and Mechatronics (ICRoM), Tehran, Iran, Islamic Republic of. 517-522. https://doi.org/10.1109/ICRoM54204.2021.9663519

Related Paper 2: Needle-Size Bending Actuators Based on Controlled Nitinol Curvatures and Elastic Structures

Kalairaj, Manivannan Sivaperuman, Bok Seng Yeow, Chwee Ming Lim and Hongliang Ren. Needle-Size Bending Actuators Based on Controlled Nitinol Curvatures and Elastic Structures. Journal of Mechanisms and Robotics 12: n. pag, 2020. https://doi.org/10.1115/1.4045646

I started this assignment by thinking about my overall goal for later on in the class. I knew from Monday’s discussion that I was most interested in working with using nitinol as an actuator in soft materials, so my first search was “nitinol soft robotics” in IEEE.

This search yielded fairly few results, and none that really caught my eye and I needed to broaden my search. I turned to Google and started searching for a more generic word for and/or related to nitinol, where I found out that its metal classification is as a Shape Memory Alloy (SMA). I hopped back into IEEE and changed my search to “shape memory alloy soft robotics” and found related paper 1.

From there, I jumped down to the paper’s references and started looking for two things: 1) a reference title that seemed a bit vaguer (more likely to be research/survey oriented, rather than a paper summarizing a single experiment’s results) and 2) an old(er) publishing date. These criteria landed me on my root paper.

Lastly, through an unfortunately unreproducible bout of random clicking, I got from the paper on Science Direct to its referenced papers page on Scopus. My root paper had 70 other different papers that had used my root as a reference for me to choose from, so I began searching the results for related keywords. Eventually, I found my related paper 2 after searching “silicon,” because I knew that, due to the nature of our class, this was a very likely soft material I would be using later on.

Polyurethane foams and 3D-printed lattice structures were covered in wax and tested at various temperatures. The results indicated that wax-coated structures have the potential to act as a much more controllable medium for robotics, allowing for controlled changes and repairs to be made to the structure’s stiffness modulus through temperature change.

Cheng, N.G., Gopinath, A., Wang, L., Iagnemma, K. and Hosoi, A.E. (2014), Thermally Tunable, Self-Healing Composites for Soft Robotic Applications. Macromol. Mater. Eng., 299: 1279-1284. https://doi.org/10.1002/mame.201400017

Paper 2: Puffy, a friendly inflatable social robot (S21 R75)

This paper (and supplementary video) discusses the purpose and features of a Baymax-esque soft robot designed to improve children’s learning environments. The video demonstrates a classroom application of the technology using a conceptual prototype, however neither it nor the article go into technical depth. That being said, it is made clear that the multi-sense interactivity and target aura of Puffy is largely possible due to it being a soft robot.

Alessandro Ubaldi, Mirko Gelsomini, Marzia Degiorgi, Giulia Leonardi, Simone Penati, Noëlie Ramuzat, Jacopo Silvestri, and Franca Garzotto. Puffy, a friendly inflatable social robot. In Extended Abstracts of the 2018 CHI Conference on Human Factors in Computing Systems, CHI EA ’18, 1. Association for Computing Machinery, 2018. doi:10.1145/3170427.3186595.

Paper 3: Electroactive textile actuators for wearable and soft robots (IEEE)

Dielectric elastomer actuators (DEAs) are thin, multilayered membranes that physically deform as a result of a voltage being applied. This paper tested the relative change in top surface area as a result of small voltages (9kV and 6kV) being applied to multiple DEA configurations. This technology can harness this deformation to create specific movements and ultimately achieve actuation from a voltage supply.

J. Guo, C. Xiang, T. Helps, M. Taghavi, and J. Rossiter. Electroactive textile actuators for wearable and soft robots. In 2018 IEEE International Conference on Soft Robotics (RoboSoft), 339–343. April 2018. doi:10.1109/ROBOSOFT.2018.8404942.