The “Walk & Flip”: The Formation of an Innovative Approach to Reading & Exercise

Introduction

I like to read as much as I can. Furthermore, as a high school student, I often have to read — reading textbooks to prepare for lessons, reading novels for literature classes, etc. I also like to exercise, which includes cardio exercises using a treadmill. When I walk on the treadmill, I often listen to audiobooks or watch videos. I rarely read. There lies the conflict. Reading physical books is difficult, especially when walking on a treadmill. Being at a different speed than the book means flipping pages often leads to ripping them out. Even worse, reaching out to carefully flip a page may lead to a lapse of focus on walking — subsequently falling and being injured. 

Literature Review

In the United States, 80% of people aged 6 years and older fail to perform enough exercise (Piercy, 2018). To get more exercise, many use treadmills. However, many also choose to watch screens for entertainment as they use treadmills. Excessive screen time is linked to poor sleep quality, stress regulation, and mental health (Nakshine, 2022). Therefore, there is value in discovering options for screenless entertainment.

Reading is a means of screenless entertainment, but is inconvenient because the book may not be supported by the treadmill and the act of flipping pages may lead to page tears because the reader is in motion while the book is stationary. Even worse, trying to slow down one’s walking speed to carefully flip a page may lead to falls and injury. 

The solution described below includes a shelf to hold the book in place, a system of servo motors to flip the pages automatically, and a hands-free trigger to flip the pages when the reader is done. The device is unlike other approaches. Audiobooks may be listened to and digital books have specialized devices (Syukuyu, 2024), but such approaches don’t work for physical books. As for automatic page-turners for physical books, some (PageFlip Lite, 2024) are for sheet music and require inconveniently loading the pages into the device by hand in advance of reading them. Other automatic page-turners (Brady, A. 2004) flip a book that rests flat on a table, rather than standing upright against the face of a treadmill. 

The Engineering Design Process

I would create a 3-D printed device to flip the pages. The device would require three components: a shelf for holding the book and moving mechanisms, a mechanism to flip the pages of the book while keeping the rest of the book still, and a mechanism to recognize when a user wants the pages to be flipped. I will print several parts (quadrants of the base, top, etc.) that would be printed to fit together like puzzle pieces. 

Caption: Pictured is a system of servos

A system of servos programmed by an Arduino, until a more cost-effective solution was found, would handle the mechanical flipping of the pages. Two would be responsible for keeping each side of the open book still. Two would be responsible for aligning a small tire next to the pages to be flipped — then spinning the tire slowly, using the traction of the tire to flip the page. 

I had several ideas for the mechanism to recognize when page flipping should occur. The first was an eye-tracking app on a phone. The second was a watch app where users tap the screen — seemingly easier than flipping a stationary object — or otherwise signal the book to flip. The third was voice control — this would be less useful in a noisy gym, but may still work at short distances. 

How did I go about this?

First, I worked on 3D-printing the shelf. Without a 3D model of the shelf, I couldn’t design the system of servos that would be attached to it. Therefore, 3D printing was my priority. While I had some experience with CAD software, I had never used a 3D printer before, having only modeled in Autodesk Fusion 360 CAD before asking a friend in my school’s Programming Club to print it at home.

I spent my first few weeks learning FreeCAD, a 3D-modeling software that was better suited for this project than the one I had learned, Autodesk Fusion 360 CAD, was. FreeCAD was better suited because it allowed for individuals to create projects that were not linked to a team; I had already “maxed out” the number of teams I was able to access. Essentially, I was paywalled by Autodesk Fusion 360 CAD but not by FreeCAD. I watched online video tutorials to assist me as I created the initial shelf for dimensions from a treadmill at my local gym, before figuring out how to break the shelf up into pieces and print each piece.

I eventually succeeded in not only drafting the 3D models but finalizing the first few pieces:

Figure 1: Model of the initial four pieces of my project’s base

Figure 2: The initial four pieces of my project’s base. They are different colors due to me printing on different machines using different materials.

Figure 3: Picture of one quadrant of the base. Includes extensions and holes to fit together with other pieces.

After the initial pieces were finished, I began working on print. I read the manuals, asked other interns for assistance, and even took a small introductory class at a DC library so I could know as much about 3D printing as possible. I was surprised — I had no idea that 3D printing could take as long as it did. I had an expectation that I would be able to print two or more pieces a day — I didn’t expect that some of my pieces would take 13 hours. Having over a dozen pieces which would take so long meant that I faced a serious constraint in printing my project, especially because I often could only use one printer at a time due to other people using the printers or when one printer broke. Worse still, my prints would often fail due to the age of printers and a need to balance between speed, material use, and structural stability through tweaking printing settings.

After printing a few pieces of the shelf and confirming structural stability, I continued to print models. I also began to prioritize printing the components of my shelf necessary for attaching the servo system to it. The servos to hold pages together would use long, hollow rectangles attached to the “fan”-like components of the servos that spun. I printed these rectangles, which included features to wrap around the servos’ moving parts and otherwise hold the system in place. I began to program the servos using an Arduino, achieving success in having the clasping mechanism, which held the book stationary as the pages were being flipped, having its code drafted and actualized — watching the servos respond to my code was exhilarating. 

I can smile knowing that I learned how to 3D-model, 3D print, and program servos using an Arduino from scratch. I am also excited to continue working on this project. Because the 3D printers are a bottleneck, I have not finished printing the prototype shelf, despite having finished the software modeling. Therefore, I have been unable to finalize and truly test my servo system. I am also aware that to have a fitness watch software application or eye-tracking application approved by the Apple Store would take considerable time. 

Therefore, this blog post describes my substantial progress so far. I hope to eventually reach my goal of being able to Walk & Flip. The theme of this project is exploring how innovation can make peoples’ exercise lives more convenient. This project has demonstrated that it is feasible to print interlocking components and begin programming servo motors to begin to put this together. Readers at home may attempt to make their own versions of this for their own treadmills; such DIY projects, if widely known, may provide an option for many who are torn between walking and flipping.

Next Steps

Next steps to expand on this project include:

1. Finishing 3D printing all components of the shelf.

1. The four parts of the base were fully printed.

2. The four parts of the front-facing vertical side were printed with mistakes, meaning a reprint may be necessary.

3. Other miscellaneous printer parts, such as those attaching to servos, were printed.

4. The top four parts as well as the back four parts have not been printed.

2. Refining Arduino code through testing the servo system with the shelf.

3. Testing the design for several sizes of books and several sizes of treadmills, possibly creating several shelf versions to match each book or treadmill size.

1. This project may become open to collaboration for such customization.

4. Finalizing a trigger system, of which there are several candidate mechanisms:

1. An eye-tracking app on a phone that causes a page flip when a user looks at the end of the book for long enough. 

2. A smartwatch app where users tap its screen — easier than flipping a delicate physical page, as a watch face cannot be torn — to signal for a physical page flip.

3. Voice control, which would be less useful in a noisy gym.

4. A timer that would flip pages at regular intervals depending on a user’s inputted reading speed. 

About the Author

Ryan Ting is a senior at BASIS DC, a high school in DC. Ryan feels a strong sense of belonging to the city he’s called home his entire life. As the Youth Attorney General and now the Youth Mayor of the DC YMCA Youth and Government Program, Ryan has worked steadfastly to prepare high school students for civic engagement. Outside of political science, Ryan enjoys providing free tutoring to middle schoolers, leading the Programming and Math Clubs at his school, working with a nonprofit, and building his 3D modeling (FreeCAD) and other Engineering skills. Hoping to become an Engineer to invent physical solutions for humanity's biggest problems, Ryan acknowledges the enormous opportunities provided to him in this city and hopes to use them to give back. 

Citations

Brady, A. (2004). “Universal design of an automatic page-turner”. https://doras.dcu.ie/17192/
Nakshine, et al. (2022). “Increased screen time as a cause of declining physical, psychological health, and     sleep patterns: A literary review”. Cureus. https://doi.org/10.7759/cureus.30051
PageFlip. Retrieved August 30, 2024, from https://www.pageflip.com/products/lite
Piercy, K. L., et al. (2018). “The physical activity guidelines for Americans”. JAMA: The Journal of the         American Medical Association, 320(19), 2020. https://doi.org/10.1001/jama.2018.14854
Syukuyu, S. K. (n.d.). SK SYUKUYU RF Remote Control Page Turner for Kindle Reading Ipad Surface     Comics, iPhone Android Tablets Reading Novels Taking Photos(Black). Amazon.com. Retrieved             August 30, 2024, from https://www.amazon.com/dp/B08T8CZYF3/

Innovations in Posture Correction

Revolutionizing Posture: The micro:bit Posture Tracker 

Jayden Adomako, Stafford County High School

    Many of us spend a lot of time sitting with poor posture, whether at work desks, using our phones for browsing, or watching TV. In all of these, we're likely to be slumped with our neck pushing our head forward, which can cause various body aches and pains, especially in our back and neck. The World Health Organization reported that over 1.7 billion people suffer from problems affecting their muscles, bones, and joints (WHO, 2021). This blog post is a first step in helping yourself or others to learn how to sit and stand correctly to avoid future posture-related problems.

What is Good Posture?

    Good posture refers to the alignment of the body, and particularly in the spine. Good posture allows for optimal functioning of muscles and joints, or what a teacher or medical professional would have you call the musculoskeletal system. Perfect posture is uncommon or rare, but would involve positioning the body in a way that minimizes strain and maximizes the efficiency of movements of your body. In standing posture, the ears, shoulders, and hips should ideally align vertically, with the body weight distributed evenly on both legs. When sitting, the spine should be in a relatively neutral position, with the lower back also supported. Your feet should also be flat on the floor, and knees at a 90 degree angle. These positions help reduce the risk of strain and discomfort and prevent long term musculoskeletal issues (Gorman et al., 2020).

The Problem with Poor Posture

    Correct posture is something that many individuals struggle with nowadays, often without realizing it. The dependency on today's technology in the modern world makes slouching hard to avoid, Whether it be at work, school, or simply at home after a long day. These slouching habits creep up on everyone, and it can lead to discomfort usually in the back area, pain, and in decreased productivity. O'Keeffe et al. (2019), reported that 80% of people who have claimed to have poor posture have also experienced chronic pain or discomfort. Other research supports this connection with poor posture and musculoskeletal pain.

The Invention: A micro-bit-Powered Posture Tracker

    My innovative wearable technology offers a non-invasive way for people to position themselves for alignment on a daily basis.My engaging invention is a wearable device created to assist in keeping the posture of your spine in check by detecting your body position in real time. It features and is powered by the micro-bit microcontroller. The micro-bit is a nice compact, inexpensive  piece of technology that integrates a sensor and can be programmed in

Invention Virginia / Invention DC Regional Expos - April 5 (UPDATED)

 Acknowledging regional educators' concerns for scheduling between seasonal holidays, Invention Virginia and Invention DC have rescheduled one week earlier on April 5, 2025.  

The deadline for registering for the online Virginia Statewide Convention remains April 21, 2025. 

Participation in a regional expo is not required to register for the state convention.

All programs are FREE to students, teachers, and schools!

More details are available at https://inventionvirginia.net/ or by email at team@InventionVirginia.net. 

Mailing list: Click here!

Virginia Tech STEM Discovery Fair - March 1, 2025

See the newly opened Innovation Campus building while learning about great STEM education opportunities in the Northern Virginia Region.

The VT STEM Discovery Fair, which will take place on Saturday, March 1, 2025, from 2:30 PM to 5:30 PM. 

The event will be located at Virginia Tech Innovation Campus, 3625 Potomac Avenue, Alexandria, VA 22305  The Campus is a 4-minute walk from Potomac Yard Metro, and paid parking is available. 

This event is collaboratively organized by College Access Collaboratives, College of Engineering, the College of Sciences, and the Innovation Campus.

The Effect of Leading Edge Slot Angle on NACA 2412 Airfoil’s Critical Angle of Attack

by Ian A. Ledford

Introduction

An aerodynamic stall occurs when the critical angle of attack is surpassed, producing insufficient lift for flight. They continue to be a significant, often disastrous problem in modern aviation. STAT Over the past few decades, several technologies have been developed in an effort to reduce the number of stalls that occur. On the leading edge of an airfoil, movable slats can both increase the camber of the airfoil and direct high pressure air towards the upper surface to delay boundary layer separation at higher angles of attack (AOA’s). Still, like most control surfaces, slats increase drag thus reducing efficiency so they are designed to retract. Unfortunately, these retracting systems add weight, potential for failure, and complexity in manufacturing.

Leading edge (fixed) slots apply the same principles as movable slats but cannot retract. Their simplicity solves the issues with slats outlined above, but they have no way of reducing the drag they create. This investigation will determine the best angle for a leading edge slot to improve an airfoil's lift at higher angles of attack, potentially delaying the onset of a stall.

Theory

Fluid traveling closely to an object is subject to the no-slip condition (the fluid has zero velocity relative to the object) because of the high decelerating effects from its viscosity. Farther away from the object, fluid travels in an inviscid flow. The boundary layer that forms between these two regions can be laminar or turbulent and plays a critical role in an airfoil's ability to generate lift.

At the boundary layer separation point, the pressure gradient reverses, causing backflow in the form of a circular flow pattern and wake. All of these effects redistribute airflow over the remainder of the wing and can lower the total lift captured. Beyond the critical AOA, the boundary layer separates too soon to produce sufficient lift, resulting in an aerodynamic stall. 

Figure 1: Annotated diagram illustrating fluid movement over an airfoil. Sourced from Aerospace Engineering Blog.

For an airfoil, the adverse pressure gradient increases as the AOA increases. Principally, higher velocity airflow can temporarily overcome a higher pressure gradient thereby delaying the separation point. Leading edge slots and slats improve lift (and consequently increase the critical AOA) using the same principle. By creating openings in an airfoil, the higher pressure air underneath is allowed to flow upwards, which in turn accelerates according to Bernoulli's principle. As the higher pressure air flows down the concentration gradient it increases the energy of the air moving over the top of the wing, pushing the boundary layer separation point further back on the airfoil. 

Experiment Setup

The Cessna 172 airfoil was selected for this experiment to represent low speed slot effects and because of its extensive presence in the aviation world. The airfoil was replicated by importing the Cessna 172’s four digit NACA code into Onshape (an open source computer aided-design program), cutting the slots through the airfoil, and extruding them to an appropriate spanwise length.

The slot widths were kept constant at 0.0125% of the chord length, inspired by a previous study conducted by the National Advisory Committee for Aeronautics airfoils on fixed slots. The study used a slot width of 2% of the chord length but it was decided to shrink that even more to further enhance the acceleration of air. It was theorized that the narrower slot would cause the air to accelerate more to maintain a constant volume flow rate. This would in turn, according to Benoulli’s principle, decrease the pressure and increase the air speed exiting over the upper surface of the airfoil. The surface area of the airfoils were kept constant at 193.5cm2 with an accepted error of 0.1cm2. The chord length and width was also constant at 8cm and 12cm respectively. 

The Pitsco AirTech-40 wind tunnel, originally designed for model car testing, was used for this experiment. The tunnel records lift in grams using two scales located approximately 3.5 inches apart at the base of the test section. The tunnel also records drag in grams by using a “drag link.” With the tunnel not specifically being designed for airfoil testing, a mount was created to articulate each wing to a given AOA. Several methods were explored before a stepper motor was selected to position the airfoil to within the accuracy of a degree. Then, a cardboard base was constructed to support the stepper motor and airfoil in the center of the two lift scales. The base also provided an attachment point for the drag link. To allow airfoils to be securely fastened but still swapped quickly, a puzzle piece connection was 3D printed using OnShape. After printing, one part of the puzzle piece was glued to each airfoil while the other part was glued to the stepper motor. Finally, an arduino stepper code was sourced online and used to control the angle of the mount.

To record the data, the wind tunnel was turned on for 5 seconds before a photo was taken of the values displayed on the sensors. These values were then recorded in a notebook. Two trials were conducted within which each airfoil was tested at the following AOAs: 0°, 5°, 10°, 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, and 25°. The tunnel's wind speed was also tested with a Kestrel 1000 Weather Meter. Lastly, testing was conducted on the mount to determine the lift and drag created. These findings were later subtracted from each airfoil's lift and drag data. 

Results

The impact of a leading edge slot on a NACA 2412 airfoil’s lift generation is illustrated by figure 2. The data table was compiled by averaging the two trials conducted with the Pitsco AirTech-40 for each test airfoil. This data was compared with the lift captured by the NACA 2412 airfoil without a leading edge slot (the control). 

Figure 2: Line graph illustrating lift performance data of each airfoil. Created using Microsoft PowerPoint. 

All the airfoils showed comparable levels of lift generation until approximately 15°, at which point the difference in lift produced by the airfoils exceeded 20 grams. All the airfoils with a leading edge slot produced more lift at an AOA of 25° than the airfoil that didn’t have one. With the exception of the airfoil with a leading edge slot positioned at 150°, the slotted airfoils failed to generate significantly more lift than the control at any other tested AOA. Figure 3 compares the lift produced by the airfoil with a leading edge slot positioned at 150° and the control. 

Figure 3: Line graph with the lift performance data from the control airfoil and the test airfoil 150° angled slot. Created using Microsoft PowerPoint. 

The airfoil with a leading edge slot positioned at 150° produced more lift from an AOA of 21° to 25° than the control. However, it generated a substantially lower amount of lift than the control from an AOA of 16° to 19°. The drag generated by each airfoil is illustrated in figure 4.

Figure 4: Line graph illustrating the drag performance data of each airfoil. Created using Microsoft PowerPoint. 

The airfoils generated comparable drag until they passed an AOA of 19°. Between an AOA of 19° to 25°, the control airfoil produced much more drag than the slotted airfoils. 

Analysis

The airfoils with a leading edge slot positioned at 120°, 130°, and 140° didn’t seem to offer a consistent improvement in lift. While they did produce more lift than the control at an AOA of 25°, they generated comparable or less lift than the control at every other tested AOA. The trend in the data clearly establishes these slot angles as ineffective in achieving the desired consistent increase in lift, particularly at higher angles of attack (15° through 25°). The airfoil with a leading edge slot positioned at 150° successfully increased the lift it generated at higher angles of attack when compared to the control. This slot position seemed to redirect a sufficient amount of fluid (air) at higher angles of attack to push the boundary layer separation point further back on the airfoil. With more laminar flow attached to the skin of the airfoil, it was able to generate more lift. 

The leading edge slots behaved differently than initially predicted when it came to generating drag. They did not produce significantly more drag at any point than the control airfoil, instead universally decreasing the amount of drag generated past an AOA of 19°. Importantly, one of the primary stages of flight that leading edge slots have been observed to produce more drag occurs during cruise. It was not possible to recreate this environment due to the limitations of the wind tunnel that was available (the typical cruise speed for a Cessna 172 could not be reached).    

The wind tunnel had several other limitations that must be considered when analyzing the data. The tunnel utilized for testing was located at Yorktown high school, and lacks any record of maintenance during its installation (15+ years). As a result, it must be assumed that there has been no maintenance conducted on the tunnel, leaving a risk that its sensors were incorrectly calibrated when the data was collected. Additionally, the wind tunnel's inability to transfer sensor readings onto a computer may have corrupted the data, as a crude photo method for data collection left a large margin for error. The drag data also has a potential for bias because the drag link was attached to the mount and not directly to the airfoil. Beyond the tunnel, limitations such as the permeability of the 3D printing filament could also have influenced the results. 

Conclusion

This experiment had several limitations stemming primarily from the constraints on available resources; however, it also had several key successes. The collected data demonstrated that a NACA 2412 airfoil with a leading edge slot positioned at 150° could improve lift at higher AOAs. It can also be reasonably assumed that certain positions of leading edge slots can actually hinder the amount of lift a given airfoil is able to generate. Interestingly, slots appear to be a way to decrease drag, albeit at the expense of lift. These initial findings can be leveraged for further experimentation in a more controlled environment. The main limitation of this experiment was the precision with which it was able to be conducted with. Better wind tunnel equipment and material testing could eliminate this and may yield better results, presenting an opportunity for further analysis. 

In short, this experiment’s findings provide a basis for further research, design, and prototyping. Based on the results of this experiment, specific leading edge slots seem capable of providing a viable solution to increase an airfoil's lift at higher AOAs, potentially also affecting its critical angle of attack. 

[1] Tom Benson, ed., "Boundary Layer," National Aeronautics and Space Administration, accessed September 28, 2024, https://www.grc.nasa.gov/www/k-12/BGP/boundlay.html.

[2] Benson, "Boundary Layer," National Aeronautics and Space Administration.

[3] Holger Babinsky, "How Do Wings Work?," Physics Education 38, no. 6 (2003): [Page #], accessed September 28, 2024, https://doi.org/10.1088/0031-9120/38/6/001.

[4] Fred E. Weick and Joseph A. Shortal, "The effect of multiple fixed slots and a trailing-edge flap on the lift and drag of a Clark Y airfoil," NASA Technical Reports Server, [Page #], accessed September 28, 2024, https://ntrs.nasa.gov/citations/19930091501.

[5] "Arduino-Beginners-EN/E14-stepper-motor /stepper-motor-back-and-forward.ino," Github, last modified 2021, accessed September 28, 2024, https://github.com/BasOnTech/Arduino-Beginners-EN/blob/master/E14-stepper-motor/stepper-motor-back-and-forward.ino.

Bibliography

Aerospace Engineering Blog. Accessed September 28, 2024. https://aerospaceengineeringblog.com/boundary-layer-separation-and-pressure-drag/.

"Arduino-Beginners-EN/E14-stepper-motor /stepper-motor-back-and-forward.ino." Github. Last modified 2021. Accessed September 28, 2024. https://github.com/BasOnTech/Arduino-Beginners-EN/blob/master/E14-stepper-motor/stepper-motor-back-and-forward.ino.

Babinsky, Holger. "How Do Wings Work?" Physics Education 38, no. 6 (2003): 497-503. Accessed September 28, 2024. https://doi.org/10.1088/0031-9120/38/6/001.

Benson, Tom, ed. "Boundary Layer." National Aeronautics and Space Administration. Accessed September 28, 2024. https://www.grc.nasa.gov/www/k-12/BGP/boundlay.html.

Microsoft. Microsoft PowerPoint. https://www.microsoft.com/en-us/microsoft-365/powerpoint.

Weick, Fred E., and Joseph A. Shortal. "The effect of multiple fixed slots and a trailing-edge flap on the lift and drag of a Clark Y airfoil." NASA Technical Reports Server. Accessed September 28, 2024. https://ntrs.nasa.gov/citations/19930091501.

About the Author

Hi! My name is Ian Ledford. I am a senior and IB diploma candidate at Washington-Liberty High School in Arlington, Virginia. I am a curiosity driven learner, with a deep passion for engineering. I have always wanted to know the “how” and “why” behind everything that I see. This past summer, I had the unique opportunity to work with fellow highschoolers and the incredible Virginia Tech Thinkabit Lab team! When I was brainstorming research project ideas, my continual fascination with flight led me to discover, through preliminary research, leading edge slots. With relatively little information available on the web, I was particularly excited to experiment with a more novel airfoil modification. Over the course of the internship and through continual trial and error, I became proficient in Onshape CAD and 3D printing. Next year, I am excited to attend a university where I can continue to explore and cultivate my passion for engineering. 

Ian A. Ledford (He/Him)

LinkedIn

ian22ledford@gmail.com