Senior Design is the capstone of Penn’s practice-integrated mechanical engineering curriculum. The two-semester senior design sequence challenges students to bring theory, skills, general knowledge, and inventive energy to bear on substantial engineering problems. There is no “typical” project and the variety is always surprising: some projects lead to marketable products; some explore a theoretical principle; some are just for fun. But taken together, they reflect the breadth and diversity of mechanical engineering. This year, we have twelve teams.

HAB Attack: A dynamic watercraft used to mitigate harmful algal blooms (HABs)

Harmful Algal Blooms, or HABs, are overgrowths of existing algae populations caused by excess nutrients and pollutants. HABs harm people and wildlife in and around a body of water by creating toxins and depleting oxygen levels in water. Current mitigation and clean-up methods require organizations to treat HABs manually, costing local governments in excess of $100,000 each year. HAB Attack is a portable craft designed to aid stakeholders in preventing and treating HABs through ultrasonic irradiation and surface aeration. It is intended for use by water treatment centers, state park rangers, and wildlife conservation programs. HAB Attack allows users the novel ability to prevent and treat local HABs. If deployed consistently through the spring and summer, the expert electrical and labor cost of running and maintaining our product is under $2,000.00 annually.

Measuring 2 feet by 3 feet and weighing under 60lbs, HAB Attack is portable. The device fits in the backseat of a car and can be easily carried to the waterfront by two people. Once in the water, users navigate the craft through both remote control and run an autonomous mode, which will command HAB Attack to treat the entirety of a designated surface area. HAB Attack leveraged research from biologists and water quality control. Optimization of the ultrasonic treatment parameters, power generated by thrusters, and the craft’s weight and dynamic behavior allows HAB Attack treating regions up to 50 acres per deployment.

Team HAB Attack is composed of Alex Choi, Nicole Ng, Sarah Ho, Thomas Swingley, and Hunter Williams and is advised by Professor Ani Hsieh.

Smok-E: An autonomous litter collection robot

Litter is everywhere, and it is not going away. Trash accumulates as part of a vicious cycle: when people see litter, they are more likely to add their own garbage to the pile. Current efforts are costly and inconvenient, or focus solely on motivating individuals to clean up after themselves. Litter is especially harmful in natural environments, stunting plant growth and poisoning hungry animals. It is unsightly and diminishes enjoyment of nature. This issue is especially problematic for campsites and outdoor areas that attract significant human presence – and thus, trash. To prevent these potential harmful effects and to preserve the sense of untouched wilderness that campers expect, park rangers and maintenance crews spend upwards of $250 and 15-20 hours per campsite per season cleaning up the litter left behind after each reservation. Considering the multitude of campsites in the U.S. alone, this is a significant amount of time and labor.

Smok-E, an automated trash collection robot, aims to attack this vicious cycle while reducing campsite trash collection costs threefold over five years. Its robotic arm can remove campsite trash ranging in size from a napkin to a glass bottle and weighing up to 250g. This system sits atop a battery-powered mobile base with an accessible litter receptacle. The robot leverages a custom-trained computer vision algorithm and path planning to navigate to and retrieve trash. Custom motor controllers allow tight integration with custom firmware and a three hour runtime. With Smok-E, campsites can remain litter-free at a lesser labor and time intensive rate, allowing for a more authentic and environmentally-friendly camping experience.

While Smok-E has been designed with campsites in mind, it can be generalized to other environments such as roadsides, community parks, and city sidewalks.

Team Smok-E is composed of Ryan Martin, Bailey Carlson, Alex Ge, Richard Prescott, and Will Vauclain and is advised by Professor Michael Posa.

Chameleo: A world of color at your fingertips

Amateur and advanced painters alike desire a way to replicate colors in their work that they may see online, in other pieces, or in physical objects and landscapes. However, mixing paint to achieve a desired color is often difficult and time consuming, regardless of skill level. One user recounts being at a standstill due to not being able to match the color of a baby’s eyes, while another user recounts having to repaint the canvas with a different color due to not being able to exactly replicate the original color.

Chameleo is an exploratory paint dispensing tool that improves color matching and mixing processes in various art industries, providing a solution that is efficient, accurate, and user-friendly. Chameleo is compact and portable (10” x 10” x 18” in size) and can be easily operated by end users open to implementing new tools into their artwork. Chameleo will leverage color theory algorithms and high-precision dispensing technology to ensure accurate color dispensing. Existing color matching app technology will provide CMYK color codes, and the system will automatically dispense paint in accurate ratios within 15 seconds; decreasing time spent mixing paint by up to 97%. In addition, the match accuracy between the desired paint color and the dispensed paint color will be within 5 on all channels of the CMYK scale.

The development of this personal paint tool requires extensive user research, stakeholder outreach, and experimentation in the areas of color matching algorithms, precision dispensing technology, and human factor design. Team Chameleo is composed of Terence Lin, Sharon Kuo, Daryn Golub, Razaq Aribidesi, and Gregory Tasik, and is advised by Professor Jenna Shanis.

Alga: Household Edible Algae Carbon Sequestration Device

Over the last decade there has been an explosion in health and eco-friendly conscious consumption. Increasing effects of climate change–propagated by carbon dioxide– has been a major driving factor behind this shift. Algae supplements are already becoming more popular and have proven success in the superfood market. Additionally, algae has ancillary properties of a high growth rate and high carbon absorption abilities. Alga seeks to capitalize on these unique properties and industry tailwinds with a household carbon sequestration device capable of being both carbon-negative and producing edible algae byproducts. A freshwater species of algae, Chlorella Vulgaris, is used as the primary mechanism due to its high carbon absorption, low maintenance, and high nutritional content. The algae species is known to contain amino acids, antioxidants, omega-3s, and other essential nutrients. The size of the device is roughly half of a mini-fridge (20 x 20 x 30 inches) with a maximum filled weight of ~160 pounds. The device is designed so that algae can be harvested every 2 to 12 weeks. The device captures CO2 at a peak rate of 0.5 kg/day, which–assuming electricity is produced from fossil fuels–offsets the daily electricity use of the device for a net negative CO2 production. The CO2 capture rate is also 110 times more than regular land vegetation given the same footprint. Current efforts are focused on adding an automated filter system and casing construction to improve user friendliness. Alga will minimize barriers to climate conscious behaviors and provide easier access to healthy food.

Team Alga is composed of Liam Costomiris, Ivan Pan, Anabelle Pham, Arjun Shukla. The primary advisor is Professor Howard H. Hu. The technical advisors are Professor Noam Lior and Professor Hugo N. Ulloa.

OneShoe: The shoe that grows with your child

Toddlers grow very quickly and their feet are no exception. Toddlers tend to grow out of a pair of shoes every three months, putting a significant financial burden on their guardians, who typically spend $35 – 50 per pair of shoes. Adults with toddlers with two differently sized feet or who wear foot braces experience the additional challenge of finding solutions to these needs. Based on a survey with 68 respondents, nearly half of guardians purchase over six pairs of shoes for their child between the ages of one to three.
We propose OneShoe, a shoe that grows from US sizes 4C to 7C, intended for children between the ages of 12 to 24 months. The shoe consists of 3 segments: The outsole, insole, and the upper. The outsole is made from thermoplastic polyurethane (TPU): a highly-manufacturable polymer with exceptional elasticity and robustness. The middle of this outsole includes an accordion structure that allows for the shoe to expand and compress as needed. Two velcro straps on either side of the sole allow for size adjustments. The insole consists of an industry-standard foam layered on top of more TPU. The inclusion of the TPU in the insole allows for the intended size to be held from the inside of the shoe. The upper–which is stitched into the sole–is made up of a fabric blend of plain woven cotton (canvas) and neoprene. The thermal properties, protectiveness, water resistance, and stretch of these materials make them ideal.
Our adult stakeholders will benefit from the reduced cost (spending 66% less of what is typically spent over the target growing period) and reduced waste (producing 5.5kg less in waste over the target growing period). Our child stakeholders will enjoy a safe, comfortable, and long-lasting shoe that they’ll be familiar with as they begin to understand the world around them.
To validate our material selection, design choices, and manufacturing methods, we tested the shoe based on the following criteria:

  • Upper sole adhesion
  • Tensile strength, elongation, and tear strength for both upper and sole materials
  • Coefficient of friction for the sole component
  • Compression energy for the sole component

Team OneShoe is composed of Sarah Musa, Jake Russo, Miranda Stern, and Jessica Sui and is advised by Professor Robert Carpick.

AgriGate: Supplementing greenhouses with direct air CO2 capture

As climate change continues to impact the world, carbon-negative solutions are needed to offset the 50 billion tonnes of CO2 emitted by humans every year. CO2 supplementation is a method that involves injecting CO2 into greenhouses to accelerate photosynthesis, leading to increased water efficiency and improved crop yield. Current methods of supplementation include burning natural gas and importing dry ice or compressed/liquified CO2, but these approaches vary in their effectiveness and cost, and all have a net positive CO2 contribution to the atmosphere. AgriGate seeks to meet the needs of growers by supplying greenhouses with CO2 captured directly from the ambient air. It is a simple, effective, and inexpensive alternative to conventional CO2 supplementation that has the immense benefit of being carbon-negative.

Our device makes use of the moisture swing adsorption process, a novel carbon capture method wherein an ion exchange resin bonds to CO2 molecules in the air and releases them when exposed to water. Compared to other direct air capture methods, moisture swing adsorption offers significant reductions in energy requirements and cost. Users simply turn on the device and AgriGate will automatically absorb and eject CO2 when needed for optimal supplementation. Each unit is designed to support 1000 ft3 of greenhouse space, and additional units can be installed to suit greenhouses of any size, accommodating both at-home and industrial applications. Through improving the environmental impact of CO2 supplementation, we hope to make greenhouses greener.

Team AgriGate is composed of Marvin Jiang, Caleb Rudick, and Pearce Nash. They are advised by Professor Peter Psarras.

SmallSADA: Improved Power Generation for Small Satellites 

Satellites are an integral part of modern life, providing everything from advance weather warnings to GPS and telecommunications. Within a decade of their existence, small sats—small ten-centimeter cube-per unit standard sized satellites—overtook large, expensive satellites in short-term missions.  While small sats permit a multitude of new space clients such as universities, scientists, and microbusinesses, their payloads are limited by in complexity and mission duration by the power generation of static solar panels.  These are rigidly fixed to the sides of the craft and cannot track the sun to maintain the most favorable angle with incident sunlight throughout the orbital period. 

SmallSADA, a two degree-of-freedom solar panel tracking assembly, solves this problem. Utilizing extra space in launch tubes, the system integrates with the top of any CubeSat. The system’s yaw axis is actuated by a motor spinning the internal spur gear rotating the entire SADA, and its pitch axis is actuated by a two-axis motor. For the solar tracking assembly, the incident angle is found by adjusting the panel to maximize the voltage across four tiny solar cells placed across the solar panel assembly.  The two degrees of freedom allow for all angles the solar panels need to be perfectly incident with the sun during orbit, mathematically and experimentally adds 50% of power in comparison to an existing rigid configuration of solar panels.

Team SmallSADA is composed of Michael Klein Wassink, Maxim Mounier, Ariana Kyimpopkin, Matheson Lodge, Alexander Dante, and Matthew Dieffenthaller and is advised by Professor Dustyn Roberts.

Solex: Sunlight Inside

Consistent exposure to sunlight throughout the day supports positive mental health and productivity. A lack of sunlight within windowless or solely fluorescent-lit office spaces have been linked to a 12% drop in serotonin and a 15% decline in productivity. Studies also show significant sleep disturbances are common in these working environments due to a decrease in the body’s melatonin regulation capabilities. Some even experience a form of depression called Seasonal Affective Disorder (SAD) as a result of these low light levels during certain seasons. 

Solex is a light box that imitates the key characteristics of the sun in order to benefit those working and living in low natural light environments. These characteristics – frequency spectrum replication, intensity fluctuations, and angle shifts – will activate proper melatonin suppression and emulate the passage of time throughout the day. 

Solex installs much like existing recessed light fixtures. The 14.5”x14.5”x4” system inserts between standard stud lengths within a wall and connects a standard voltage source. Within the system, LED’s with blue and amber wavelengths are combined to achieve light spectrum with the greatest health benefits. Rotating mirror blinds controlled by a stepper motor mimic the sun’s path.

Team Solex is composed of Marco Armendariz Gonzalez, Martine Bernard, Ethan Cody, Matthew Mangine and Walter O’Meally is advised by Professors Igor Bargatin, Peter Harnish and Jennifer Lukes.

Orble: A fully commercial automatic bubble tea machine with the footprint of a soda fountain

Bubble tea is a tea-based drink that incorporates tapioca pearls (boba), creamer, and sugar. Consumers are drawn to the drink for its variability, opportunity for customization and its signature sweet yet refreshing taste. The bubble tea market size is evaluated at $2.4 billion and is expected to reach $4.3 billion by 2027.

Bubble tea is predominantly served in dedicated shops and current production methods are inefficient and expensive. Presently, labor and storefront rental costs account for 52.4% of the average shop’s revenue with some facilities taking up to 1500 sq. ft. Bubble tea production methods cannot currently keep up with consumer demand and a reduction in production constraints could make this drink more accessible and open up new markets.

Our solution, Orble, is a commercial automated bubble tea machine that can be installed anywhere a waste line, water, and electrical services exist. The machine is compact with a footprint of just 1x1m and height of 1.7m, requires only three hours of service a week, and serves drinks in 3-5 minutes. Orble conducts the full bubble tea production process including (1) storing and cooking boba pearls, (2) mixing drinks from various powdered ingredients, (3) dispensing the cup, (4) dispensing the boba pearls, mixed liquid and ice into the cup, and (5) heat sealing the lid. The system need only be restocked by an employee after every week and cleaned every 3-5 days. Orble uses the same quality ingredients as bubble tea shops, enabling businesses to offer a consistently delicious drink with the touch of a button.

The team is composed of Esther Amao, Sophia Anzai Takahashi, Lada Korotaeva, Nastassja Kuznetsova, Sarah Tadlock and is advised by Professor Mark Yim.

ELEVATE: The Retrofittable Standing Desk Converter

Adjustable standing desks offer physical and mental health benefits, and the market is expected to see a 50% increase in the next 5 years. However, there currently exists a barrier to entry for potential standing desk customers: the only two options are to buy a whole new standing desk or a tabletop standing desk converter. The former option generally costs upwards of $350 and is not portable, while the latter option is clunky, uses space inefficiently, and is manually operated. There is currently no suitable product on the market for customers looking for a portable and electrically operated solution, nor for customers who want to easily retrofit their own desk. 

Our solution, ELEVATE, is portable, inconspicuous, retrofittable, compatible with the majority of existing desks, and provides identical performance to typical standing desks, all while costing less than $300. ELEVATE achieves these characteristics by using four independent motorized risers positioned under the desk legs and a single desk-mounted button panel for control.

Customers looking to retrofit their desks with ELEVATE will be happy to find that it meets or exceeds all the performance characteristics the market has come to expect of standing desks. These characteristics include >300 [lb] load capacity, 1.5 [ft] of total adjustability, 0.5 [in/sec] lifting speed, and a seamless and reliable user experience. Additionally, customers will find that, with ELEVATE, they are not restricted by limited desk options; ELEVATE has been designed to maximize the number of desks it is compatible with, so, whether it is an architect’s drafting table or a heavy gothic desk, they can ELEVATE it!

Team ELEVATE is composed of Griffin Addison, Darrion Chen, and Jonathan Lee and is advised by Professor Bruce Kothmann.

Boreas: A temperature regulating shoe

Over 20 million people in the US alone experience elevated foot temperatures that impact their health, quality of life, and freedom of movement. The causes of this elevated temperature are broad and include diabetes, erythromelalgia (EM), peripheral neuropathy (PN), and Raynaud’s. The benefits of lowering elevated foot temperatures are equally broad and include improved medical outcomes and comfort. For example, recent work from the Journal of Diabetes Science and Technology showed that lowering the foot temperature of diabetics experiencing PN by 5 °C significantly reduces overall discomfort and the risk of foot ulcers. For those suffering from EM, PN, and Raynaud’s, daily activities that require mobility are often encumbered by pain and swelling, which can be reduced through cooling.

A solution to cool the feet of those experiencing elevated foot temperatures that integrates with active to semi-active lifestyles would be of great benefit to many, but the demands of the solution space are challenging. A viable solution must be light, be small, and provide intended benefit for up to 4 hours at a time. A recent solution prototyped at the University of Texas Southwestern Medical center leverages a water-cooled insole connected to a bulky, calf-mounted heat exchanger. This solution has no verified results and is uncomfortable to use, while all other solutions on the market fail to reach desirable levels of either efficacy or practicality.

Boreas is a cooling shoe that will utilize active and passive cooling technology to reduce the foot temperatures by up to 5 °C for a period of 6 hours. The Boreas shoe will incorporate a Peltier element directly in a temperature-monitoring sneaker, and that system will work in tandem with passive cooling elements to reduce the user’s foot temperature effectively and efficiently to comfortable and, most importantly, healthy levels.

Boreas is composed of Thaer Alaggad, Patricio Ramirez, and Adam Salahdine and is advised by Professor Jennifer Lukes.

CompAction: A household recycling compactor

Storage space for bulky, empty recyclables is a common barrier to recycling for those living in urban environments and space-limited homes. Half of all recycling collection is weekly curbside pickup, leaving households with overflowing recycling bins between pickups. Over half of the 49 stakeholders we surveyed take out their indoor recycling collection two or more times per week, and 65.3% indicated that the volume their recycling bin can hold is an important factor for them. 

Our solution to this storage problem is CompAction, a hand-powered recycling compactor that sits above most existing recycling bins. Recyclables are placed into the compaction chamber from above; the user turns a crank roughly 25 times to compact the recyclables by 65-75%, and a sliding drawer at the bottom of the system releases the compacted recyclables into the bin below. The process of removing recyclables from the home is unchanged, but the necessary frequency is decreased to no more than once a week. The system is anticipated to reduce the average storage volume of recyclables by 50%.

CompAction uses a double scissor mechanism with a dually threaded lead screw to move a compaction plate. The system is designed such that the mechanical advantage increases from 12:1 at the start, up to more than 300:1 during compression. With a user input of 15lbs, this mechanical advantage is sufficient to provide a crushing force of over 900 lbs. MTS testing of common recyclables revealed that is the upper limit necessary for tough metals and plastics. 

Team CompAction is composed of David Candia, Tillie Donover, Will Schlatterer, and Ethan Schwartz and is advised by Professor Jordan Raney.