Friday, April 9, 2021

Critical reflection

 

Module reflection

At the beginning of the course, I was quite nervous about what this course has installed for me. As English has been my weakest language, I am worried that I could not communicate well. Throughout the course, I feel that it has helped me to speak more fluently and also write more concisely. In the beginning, students are asked what are the key things they want to learn by the end of this course, mine was speaking fluently and writing concisely. There are many activities that, encourage students to practice their writing and speaking skills. 

I like the way this course has been conducted, as it gives students many opportunities to hone their writing and speaking skills. Activities such as writing a formal letter and design summary, taught me how to write fluently, concisely and identify the mistakes that I often make while writing. After completing our formal letter and posting on the blog, students are required to comment on each other posts to give constructive feedback and point out what were the mistakes they made. The feedback section, allows me to learn much faster from other people's mistakes. As for speaking, there are many times where I need to present to others on the key points for certain topics like what is considered a good PowerPoint slide and what are the do and don't to do for PowerPoint slides. These small group presentations enable me to slowly, get used to speaking to my peers and gain confidence. 

I believe that in the future, these skills will be very useful in the workforce. As engineers, there will be many chances, where we have to give a presentation or report to our superior about our task progression. The presentation skills that we learned such as posture, tone, and eye contact will enable me to look confident and professional.


Project reflection


The technical report project has taught me the importance of teamwork, I am fortunate to be part of Green Goer, all my members are very capable and talented. Initially, when I heard that the proposal word requirement is 2000 words, I was intimidated by it and thought it would be a difficult task. However, with the help of each member, we slowly completed the proposal, which seems to be a daunting task, but with the help of one another, we can complete it. I learned what is a good PowerPoint slide should be like. A good PowerPoint slide should consist of only keywords and it would be even better if it can be elaborated by using images. Lastly, I also learn how to give a good presentation. 

In the past, I would use to cram all information onto my slides and thought that the audience would read the slide and understand. However, too many words on the slides would bore people and this is not the best way to convey information. I realize that the slide should just be a complementary tool, for the presenter to capture the attention of the audience. After making my slides to be short and concise, I felt more relaxed and easier to present, as I was able to freely explained in my own words. 

Speaking confidently and writing fluently are the key skills that I think would help me in my future career. It would help during interviews, presenting, or even writing a summary report of the product to let customers know what are its features. These would give me an edge in the workforce, as nowadays most people are working from home, employers emphasize more on good communication skills for the team to be on the same page.


Best regards, 

Sum Jin Yao 

Summary Analysis Draft #4

MEC 1281

Summary Analysis

Draft 4

By Sum Jin Yao

9 April 2021

According to the article "Soft robotic arm uses flexible sensors to understand its position" by Matheson (2020), MIT researchers have found a way to program a soft robotic arm to understand its structure in 3D space, using "motion and position data from its sensorized skin" (Rob.M, 2020).

 These soft robots are built from highly flexible materials, alike to "those found in living organisms" and are supported as "safer, and more adaptable, resilient and bioinspired alternatives to traditional rigid robots". Traditional sensors reduce a soft robot’s functionality and also complicate its manufacturing process.

 The researchers describe it as a system of soft sensors that wrap over the robot's body and that feedback to the internal AI to provide the robot "awareness of motion and position of its body". The article mentions their future goal is to advance artificial limbs, to be skillful to grip and operate objects in the environment, and also to incorporate body sensors in robotics.

 The soft robot's materials have "piezoresistive" properties. This means when its original shape undergoes any physical changes, its electrical resistance changes with it. The material shape is "inspired by kirigami”, with a variety of patterns etched on the rectangular silicone sheets. This changes the elastic of the material. However, I believe that the disadvantages of a piezoresistive sensor --- thermal dependence and external stresses --- outweigh its advantages.

 One of the disadvantages of the piezoresistive sensor is that the pressure sensor output varies under different temperatures. This is backed by the research article "Effects of Temperature and Residual San tresses on the Output Characteristics of a Piezoresistive Pressure Sensor", written by Anh Vang Tran. et al. (2019) stating that "temperature variations can change the values of the resistors". Additional supporting article (Liu, Y. et al., 2016) referring that higher temperatures will cause a drift in sensitivity output. Another problem that is resulted from high temperature is current leakage. Liu Yan, et al. (2016) said that when the temperature is above 150 degrees Celsius, there will be current leakage and reverse current flow. This will lead to an inaccurate sensitive output. The other problem with high temperatures is that metals such as aluminum, gold, or titanium will diffuse into the silicon membrane. Thus, silicone can only function as it is intended under a certain temperature, which greatly limits its use.

 Another disadvantage of the piezoresistive sensor is that external stress can occur during the processes of chip fabrication and packaging, which will affect the performance. This is supported by the research article "Thermal-Performance Instability in Piezoresistive Sensors: Inducement and Improvement", written by Liu Yan, et al. (2016) states that "There are mainly three sources of performance perturbation in the fabrication and packaging". The piezoresistive sensor is fabricated by placing resistors on top of the silicone membrane that is in high-stress regions (Anh Vang Tran. et al., 2019). The membrane requires fabrication before resistors can be placed on top of it. During this fabrication residual stress such as thermal, intrinsic, and quenching stresses are formed in the membrane. This would affect the output of the piezoresistive sensor.

 In conclusion, the disadvantages of the piezoresistive sensor, temperature dependence, and also external stresses that occur during processes of chip fabrication and packaging, outweigh its benefits. These disadvantages make the device not compatible in various extreme climate environments and also are more likely to make it prone to inaccurate sensor output.

 

References

Matheson, R. (2020, February 16). Soft Robotic Arm Uses Flexible Sensors to Understand Its Position. Control Engineering. www.controleng.com/articles/soft-robotic-arm-uses-flexible-sensors-to-understand-its-position/

Liu, Y., Wang, H., Zhao, W., Qin, H., & Fang, X. (2016, November 24). Thermal-Performance instability in piezoresistive sensors: Inducement and improvement. NCBI. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5190965/

Anh, V., Zhang, X., & Zhu, B. (2019, February 26) Effects of Temperature and Residual Stresses on the Output Characteristics of a Piezoresistive Pressure Sensor. IEEXplore. https://ieeexplore.ieee.org/abstract/document/8653271

Avent Abacus. (2019) Capacitive vs piezoresistive pressure sensors. https://www.avnet.com/wps/portal/abacus/solutions/technologies/sensors/pressure-sensors/core-technologies/capacitive-vs-piezoresistive-vs-piezoelectric/


Critical reflection

  Module reflection At the beginning of the course, I was quite nervous about what this course has installed for me. As English has been my ...