This week I attempted to make a 2-part mold version of the heart I made previously.

As you can see, the right half of the mold had a bunch of bubbles, but this ended up not being an issue at all for that half of the mold as almost all the bubbles popped and weren’t cast in the mold, but might have contributed to the issues I had with the two part mold. Unfortunately, my two part mold didn’t work totally correctly because of a big bubble on the right side (pictured below). I play to try to correct this by filling in the area with silicone, but I haven’t had the chance yet to do this.

Daniel

This week, I modified my previous attempt at two part mould by making adding a ceiling to the texture with holes throughout the top of the structure. The plan was to fill the bottom half of the mould with silicone then press the top half down into the liquid. The excess liquid would then be pressed through the holes on the top while the inside shape remains. Here are the Solidworks files:

Unfortunately, the process did not turn out as I hoped. Although the texture ended up in the right place, the silicone ended up not being flush to the surface again. This seemed strange to me because I added enough silicone for it to spill out the holes on top as planned. However, this issue still occurred. The placement of the holes prevented large pockets of air from being trapped during the process of pressing the texture into the mould so I suspect if might have something to do with the surface tension of the silicone drawing it closer onto the textured parts of the top mould, although this is just a guess.

Unfortunately, the second half of the mold misprinted and the replacement didn’t come through in time so I was only able to test one side. The casting process was relatively successful but still need some refinement. I was able to have the channels rest at the right height and also have the fillet on the other side. However, because I had left the raft on the texture side of the mold, I did not realize that the mold did not fill completely up. I first poured silicone into the mold to fill the bottom, added the texture, then filled around the texture. However, I should have probably filled the mold with silicone first then added the texture in afterwards.

Silicone heart sketches. Deciding between having two chambers, 4 chambers, etc. Could be made with a two part mode or with an open mode.

Materials + Equipment:

• Near clear Ecoflex Silicone
• Low pressure hydraulic pump
• Water Reservoir/tank
• Syringe/hand pump
• Dyes (Red/Blue)
• Valves
• Tubes

Joint Bibliography:

Paper | Design and Characterization of a Miniature Hydraulic Power Supply for High-Bandwidth Control of Soft Robotics

While this paper did not have too much direct application to our project, it describes the parameters a power source might have to sufficiently power hydraulics for a soft robotic application.

Padovani, Damiano, and Eric J. Barth. “Design and Characterization of a Miniature Hydraulic Power Supply for High-Bandwidth Control of Soft Robotics.” In 2020 3rd IEEE International Conference on Soft Robotics (RoboSoft), 345–50, 2020. https://doi.org/10.1109/RoboSoft48309.2020.9116049.

This project would be a pneumatic heart and lungs linked to a participants heartbeat/breathing. would be collected in real time through This could create an interesting out of body-like experience where the movement of an external object is linked to one of your core subconscious functions. The goal would be to make people more aware of a process we usually don’t see, but is essential to our lives.

Creative Requirements

General Requirements:

• Aesthetically, I’d like the silicone heart and lungs to be a translucent and slightly abstracted version of the real organs involved. The form should ideally resemble the actual organs involved to move and function in an accurate way when inflated. However, I complete accuracy is secondary to having a more cohesive aesthetic.

• While the lungs might be able to be pneumatically actuated to resemble the movement of actual lungs by inflating and deflating them, it might be necessary to abstract the movement of the heart because of its combination of muscles and valves through its four chambers. I think the most important thing would be to retain the general shape and to try to mimic a two part movement that matches the “ba-dump” sound the heart makes.

Critical Path

• Participant heartbeat would be collected through an existing Arduino sensor and
• Participant breathing could be measured using an existing technique that measures the expansion of the abdomen when breathing with a rope.
• Heartbeat/Breathing data is fed to an Arduino which allows air through valves intermittently as the participant breathes in/every heart beat.
• The silicone heart and lungs inflate/deflate.

Proof-of-concept

A potential first step would be to mould and cast a prototype for the lungs to better understand how they would inflate differently based on different thicknesses and tubing arrangements.

Description:

• Pneumatic hand powered umbrella. Umbrella with sacs underneath the hinges for the canvas connected to a pump in the handle. Squeezing the handle inflates the sacs and opens the umbrella. Alternatively, the whole cover could inflate. The goal would be to redefine the core interaction of opening an umbrella, not so much as to improve its functionality, but to make the experience feel more organic and playful.

Google Patent:

https://patents.google.com/patent/US6354314B1/en

• Hydraulic/Pneumatic heart/lungs linked to a person’s heartbeat/breathing. This idea would involve creating an external heart/lungs that are linked to your own bodily functions. This could create an interesting out of body-like experience where the movement of an external object is linked to one of your core subconscious functions. The goal would be to make people more aware of a process we usually don’t see, but is essential to our lives.

Art/Sculpture:

The Lungs

Research Paper:

“Soft Robotic Surrogate Lung | ACS Applied Bio Materials.” Accessed February 8, 2022. https://pubs.acs.org/doi/10.1021/acsabm.8b00753.

• Plant thermometer: plant filled with veins that contain a low boiling point fluid. As the temperature in the room/surroundings vary, the fluid inside exerts more or less pressure on the surrounding plant walls. When the temperature is low, the plant appears to wilt, when the temperature is high, the plant appears to perk up. The goal would be to create a playful thermometer that gives a rough estimation of the temperature at the time.

Research Paper:

Wang, Yecheng, Kun Jia, Shuwen Zhang, Hyeong Jun Kim, Yang Bai, Ryan C. Hayward, and Zhigang Suo. “Temperature Sensing Using Junctions between Mobile Ions and Mobile Electrons.” Proceedings of the National Academy of Sciences 119, no. 4 (January 25, 2022). https://doi.org/10.1073/pnas.2117962119.

Art Project | Cypher

Sculptural installation that combines a soft robotic body with a VR interface. The sculpture detects the proximity of the audience and change its shape accordingly. The VR headset allows the user to change the shape of the simulation through natural hand gestures. As the user changes the shape of the VR simulation, the robot moves real-time, aligning the physical and digital transformations.

http://www.ozeloffice.com/home#/cypher/

Artist Intentions

The artist intends to create an experience that brings the physical and digital world together. A user interacting with the VR environment causes corresponding changes in the physical environment through the soft robotic form.

Brainstorming

This art piece has already applied soft materials in the physical form of the sculptural portion. An alternate way soft materials could be used to achieve a similar affect could be replacing the pneumatic bubbles with a different method of deforming shape. This could include deforming fabric by pulling or stretching it, creating silicone tendrils or arms, etc.

Reference Paper | Cabbage Gripper

This paper created a thermally actuated soft robotic gripper inspired by the structure of veins in cabbages. The gripper was created with a composite of paper and PLA with 3 “leaves” arranged in a circle to grip objects as they curl toward the center.

Hu, Fuwen, Limei Lyu, and Yunhua He. “A 3D Printed Paper-Based Thermally Driven Soft Robotic Gripper Inspired by Cabbage.” International Journal of Precision Engineering and Manufacturing 20, no. 11 (November 1, 2019): 1915–28. https://doi.org/10.1007/s12541-019-00199-6.

Application

A potential way that cypher could be modified to adopt the cabbage gripper’s technology would be changing the shape of the the sculptural potion and visuals of the virtual environment to resemble a plant-like form. This might look something like a pineapple or frond like shape or more distantly a tree like structure with cabbage-like curling leaves. Changing the technology involved creating the form of the sculpture might drastically change the mood and visual impression of the work. Currently the form and VR portion suggest a very alien, abstract, surreal experience. Changing it to a more plant-inspired form may shift the experience to a more soothing, naturalistic tone.

I found this article through the EBSCOhost database through a ‘soft robotics’ search. This particular paper was interesting to me because of the focus on creating a sensory experience that focused on touch in particular. Because touch is often neglected in art, the idea of using soft robotics to mimic skin and human movement and behavior was really interesting.

Budak, Ece Polen, Onur Zirhli, Adam A. Stokes, and Ozge Akbulut. “The Breathing Wall (BRALL)—Triggering Life (in)Animate Surfaces.” Leonardo 49, no. 2 (April 1, 2016): 162–63. https://doi.org/10.1162/LEON_a_01199.

Informal Resource | Sonō

Filtering through Google search results, I found the work of Jonas Jørgensen. This project in particular explores the idea of what a soft robot should sound like. The researchers focused on matching the form of the robot ‘creature’ with the sounds it made based on the sound design of movie monsters.

Bering Christiansen, Mads, and Jonas Jørgensen. “Augmenting Soft Robotics with Sound.” In Companion of the 2020 ACM/IEEE International Conference on Human-Robot Interaction, 133–35. Cambridge United Kingdom: ACM, 2020. https://doi.org/10.1145/3371382.3378328.

This paper describes an new method of providing pressure for pneumatic soft robots through heating low-boiling point fluids with a compliant heating mechanism. It also discusses some potential applications of this method as well as the benefits and limitations of this method.

Garrad, Martin, Gabor Soter, Andrew T. Conn, Helmut Hauser, and Jonathan Rossiter. “Driving Soft Robots with Low-Boiling Point Fluids.” In 2019 2nd IEEE International Conference on Soft Robotics (RoboSoft), 74–79, 2019. https://doi.org/10.1109/ROBOSOFT.2019.8722812.

Notes:

• During the introduction, the paper does well to establish the range of existing pneumatic actuation technologies and the need for for a niche and improvements their proposed system would occupy.
• The explanation of the thermodynamics of a LBPF elastomer actuator was slightly confusing to me and too a few rereads to understand. I think this is because the writers assume that some physical interactions are common knowledge and do not take the time to state the reasons behind some interactions.
• The explanation behind the relationship between the heating element, liquid volume, and container volume is largely well explained. The accompanying charts help explain the dynamics between heat applied and pressure well.
• One thing I was confused about was the mention of how serpentine patterns were used to avoid “asymmetrical heating from current fringing.” I did not know what current fringing meant at the time.
• One concern I had reading this section was how all the tests were conducted with fixed volume vessels. However, earlier in the paper, the author had mentioned that in practice, vessels may not be fixed due to the use of soft materials. While underlying assumptions may lead one to assume the change might be small enough to be negligible, I would have appreciated more explicit explanation.
• I appreciated the step by step walk through of the fabrication process and the notes on how some modifications might be necessary to ensure the LBPF actuator works most efficiently.

General Review Criteria

1. Originality. All papers must present original work.

The paper appears to present original work with sources cited indicating where the paper was drawing off of the previous work of other researchers.

2. Novelty. We welcome big idea and provocative papers, even if they may not be perfectly implemented. We also welcome papers that bring together different disciplines and approaches.

This paper proposes a new form of pneumatic actuation that builds on the previous work of others. While other papers had made use of low boiling point fluids in the past, the addition of a heating element as well as other modifications make the interaction novel.

3. Relevance. All papers must be relevant to the field.

The paper’s premise and result is relevant to the field of soft robotics. It proposes a new way of producing pneumatic actuation that is relevant to a niche in the field. Based on the paper’s conclusion, it should afford further improvement and capabilities in the field of soft robotics in the future.

4. Soundness. A paper needs to be technologically and/or methodologically sound based on the criteria generally used for that technology or method within a given field.

The paper’s methods of experiment and measurement seem to be sound. Details on methods of measurement and materials used are provided.

5. Technical detail. Please provide adequate details to indicate what was done, how the data were collected, sample size and characteristics, what type of robot was involved, etc. Authors should use correct terminology for their methods to avoid being evaluated against the incorrect set of criteria.

I believe the data were collected with the right procedures and with detailed terminology. The authors were careful to include detailed information accompanying all the procedures and experiments they conducted, including component names, amounts, and methods of measurement.

6. Accessibility. All papers must be written to be accessible for a broad, interdisciplinary/multidisciplinary audience.

While the paper is generally accessible through its step by step explanation of the physical processes behind how the mechanism operates, I occasionally found myself having to re-read a section because the article made the assumption I had background knowledge about some of the physical processes involved. While I was able to reason backward from the conclusion, which speaks to its accessibility, I think a slightly deeper explanation could make the article slightly more readable.

Referee Form

1. Do you have any conflict of interest in reviewing this paper? A “conflict of interest” is defined as follows:
   1. Ph.D. thesis advisor or advisee
   2. Postdoctoral advisor or advisee
   3. Collaborators or co-authors for the past 48 months
   4. Any other individual or institution with which the investigator has financial tiesYes/no. If yes, please disqualify yourself instead of proceeding. 

No

1. Expertise. Provide your expertise in the topic area of this paper.
   • 4 – Expert
   • 3 – Knowledgeable
   • 2 – Passing Knowledge
   • 1 – No KnowledgeSingle choice. 

2

2. Summary. Please summarize what you believe are the paper’s main contributions to the field of soft robotics.Please write a short paragraph. 

The paper proposes a new way of producing pneumatic actuation with far more flexibility and much less strain energy wise and in terms of safety. Based on the paper’s conclusion, it should afford further improvement and capabilities in the field of soft robotics in the future.

3. Strengths and Weaknesses. What are the main strengths and weaknesses of this work? Does the paper have strengths in originality and novelty?Please write a short paragraph. 

I think the paper’s strength is in the novelty of the mechanism it proposes and in how it fills a niche in the field. It is also strong in how it explains each process step by step and includes details of the process. A slight weakness this paper might have is that it might not take the extra step to explain a process that makes it more easily accessible

4. Soundness. Are the ideas, algorithms, results or studies technologically/methodologically sound?Please write a short paragraph arguing for the strengths and weaknesses of the work. 

I believe the paper is methodologically sound. The data were collected with the right procedures and with detailed terminology. The authors were careful to include detailed information accompanying all the procedures and experiments they conducted, including component names, amounts, and methods of measurement.

5. Related Work. Does the paper adequately describe related and prior work? Please write a sentence or short paragraph. 

The paper adequately describes previous work. In the introduction, it provides an overview of the options available in the field of pneumatic actuation for soft robotics. It draws from a number of papers to describe the techniques that are currently used as well as their strengths and weaknesses. It then uses that information to justify the approach the paper takes as well as the niche it intends to fill.

6. Presentation. Is the paper well organized, well written and clearly presented? Please write a sentence or short paragraph. 

I believe the paper is well written and presented. The ideas and thought process presented logically follow each other and are explained throughly and and clearly at each point in the paper. Although, I had to reread a few sections of the paper, the step by step explanation allowed me to deduce the thought process behind each step.

7. Suggestions. Do you have suggestions for improving this paper?Please write several paragraphs detailing specific points of the paper which merit reconsideration. Be sure to address the text, figures and tables, mathematics, and grammar and spelling. 

My suggestions for improving the paper are relatively minimal. In places the reasoning might have been improved slightly to make the paper more accessible. For example in this section discussing the mechanics behind low boiling point fluids, the authors write: “A consequence of using a fluid which is close to its boiling point is that the saturation vapour pressure will also be large. When such a fluid is injected into a sealed vessel, it will evaporate until the pressure inside the vessel reaches the saturation pressure. This places a fundamental limitation on the lifespan of pouch motor style actuators driven by low-boiling point fluid.” Because I did not know what saturation vapor pressure meant before reading the paper, I had difficulty understanding why this property limited the lifespan of the pouches. It was only by reading the following section that I was able to look back and understand what this section meant. While more readers more knowledgeable about the field may not have an issue, a brief explanation about saturation vapor pressure or how it affects pouch lifespan would have been appreciated.

Other than occasional instances like the one described above, the text, figures, and tables are clear in their labeling, context, and conclusions. The math, grammar, and spelling also appear to make sense.

8. Comments to Committee (Hidden from authors). Does the paper have enough originality and importance to merit publication? Is the paper relevant to the field? These comments will NOT be sent to the authors:Please write one or more paragraphs as needed to justify your review judgement. 

I believe this paper has enough originality and importance to merit publication. While previous papers had made use of low boiling point fluids in the past, the addition of a heating element as well as other modifications make the interaction novel. Additionally, the paper’s premise and result is relevant to the field of soft robotics. It proposes a new way of producing pneumatic actuation that is relevant to a niche in the field. Based on the paper’s conclusion, it should afford further improvement and capabilities in the field of soft robotics in the future.

1. Overall Rating. Provide your overall rating of the paper (5 is best)
   • 5 – Definite accept: I would argue strongly for accepting this paper.
   • 4 – Probably accept: I would argue for accepting this paper.
   • 3 – Borderline: Overall I would not argue for accepting this paper.
   • 2 – Probably reject: I would argue for rejecting this paper.
   • 1 – Definite reject: I would argue strongly for rejecting this paper.

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