External Mentors Program


Prof. Carney is always happy to have help or just be given the chance to brag about his students. Contact him anytime.

Program Summary

Our mission is to transition seniors in electrical engineering into professional careers. We do this through a one-semester design project that runs from conceptualization through construction and testing. Our top priority is the educational experience of the undergraduate students in our course. We appreciate the intellectual contribution of our partners who come to us from outside the course and hope to encourage participation through this program.

An external mentor may suggest interesting problems and advise teams that select those problems. With graduate Teaching Assistants (TAs) acting as internal managers and mentors, external mentors may select a level of involvement with which they are comfortable. The partnership benefits the students primarily by presenting them with challenges and advice beyond that we can provide internally and by giving them access to potential employers and extra resources such as funds, parts, and technical expertise.

We hope that our external mentors will find the program deeply rewarding. During the course of the semester many of our students grow intellectually at a rate discernible day-to-day. They are smart and humble and hard-working and are excited about making the world just a little bit better. Our undergraduate program is consistently ranked in the top five nationally, usually second. We hope this program will be a good opportunity to interact with potential hires and to expose your organization to a group of soon-to-be world leaders in engineering.

Students are free to propose their own problem or to choose a proposed problem. This freedom is part of our strategy to provide students a chance to work on a project optimally matched to their own strengths and interests. We foster an attitude of ownership of the project by the students and put the rewards and responsibilities of the project in their hands. This is their last and greatest opportunity to excel in our program and find their true potential. As a group, they rise to the occasion.

Problem Statements

External mentors begin their participation by crafting an appropriate problem statement. The course director, Prof. Carney, or the instructor for the current semester is happy to work with prospective mentors to produce a good problem statement. Problem statements must at least be vetted by the instructor. Please see the contact information below.

Projects must have a circuit design and construction component. Most good problem statements are open enough to allow a solution that includes such components. Please try to avoid problem statements that have only software solutions. In the past we have had algorithm oriented projects that included the construction of special digital circuits to handle part of the processing, so a little creative thinking can bring almost any problem into the scope of the course. Additionally, problem statements, like the projects they spawn, must strike an appropriate balance among competing requirements.

Good examples

From a member of the faculty:

Every summer, many kids die in overheated cars left in the sun. Fix this problem.

From a member of the faculty:

In my lab I need to monitor changes in the position of a stage with 20nm precision. I have a HeNe laser and that could be part of an optical solution.

From a member of the insurance industry:

There is a signature of impending failure in wires that spark electrical fires. We can provide you with data on this behavior. Build a sensor system to detect impending electrical fires. Parts costs must be under $100.

From a campus project:

We are building an all electric car as part of a large project. We need a system to regulate the output of regenerative braking and integrate with a battery charging system that includes other sources (solar and wall power). We have specific tolerances for ripple and bounce. A primary challenge is protection of the generators. Detailed requirements are given in the available background document as well as a description of the larger project. Finances for parts and supplies are available up to $2000.

Bad examples

From a hypothetical member of the faculty (specifying the solution):

Every summer, many kids die in overheated cars left in the sun. Connect a temp sensor to a voltage comparitor and a latch. When the latch goes high have the bluetooth module I will give you send a message to the OnStar system in the car asking them to check for passengers.

From a hypothetical member of the faculty version 2 (unrealistic):

Every summer, many kids die in overheated cars left in the sun. Build a machine to teleport endangered children to safety.

From a hypothetical member of the insurance industry (specifying the solution and too easy):

There is a signature of impending failure in wires that spark electrical fires. We can provide you with data on this behavior. Use a current sensor, an ACS714 built into the circuit shown in the attached diagram, to feed the A/D converter I will give you. Then write code to do matched filtering to select dangerous signals.

From a hypothetical campus project (solution given):

We are building an all electric car as part of a large project. We have designed a system to regulate the output of regenerative braking and integrate with a battery charging system that includes other sources (solar and wall power). We need you to build the design. Finances for parts and supplies are available up to $2000.

From a hypothetical campus project (unrealist):

We are building an all electric car as part of a large project. We need a system to regulate the output of regenerative braking and integrate with a battery charging system that includes other sources (solar and wall power). We have specific tolerances for ripple and bounce. A primary challenge is protection of the generators. Detailed requirements are given in the available background document as well as a full description of the project. The circuits must be 95% efficient and we have no budget.

Presenting in person

Every semester we have several external mentors come talk to the class during the first two lectures (the first two Wednesday afternoons of the semester). We ask that the presenters be brief (5 minutes) and suggest that they stay for questions after the end of the lecture. We can provide a projector and internet access to aid in the presentation. We are very happy to have personal appearances.

Donations of Equipment and Money

(Contact)

We do not require a fee to participate in the senior design process. We consider the contribution of time and intellectual effort to be significant. A good idea brought to us by an external mentor is a benefit for the students. However, our budget is limited and expensive projects simply cannot be completed without additional financial or material support. Sometimes external mentors are able to make available special equipment or supply parts, sometimes they are able to make cash donations.

In addition to the marginal costs of a project, please also keep in mind the cost of the support network ( teaching assistants, instructors, lab managers, etc) as well as the capital investment in equipment in the department in the millions of dollars. We encourage companies interested in mentoring to consider making a contribution to the department to help defray these costs. Gift money left over from a given grant will be placed into the class general fund which is used for parts for all students. We also encourage the donation of equipment and parts. Typical donations from large companies have come in $5000 increments and donations from small, local businesses have been in $1000 increments. These are suggested starting points and any support at all is appreciated.

We are always happy to work with schools, nonprofit organizations and individuals on good works projects to improve education, overcome handicaps, or contribute to the life of the community. We understand that these organizations face even greater financial hurdles than we. Indeed, the flow of material on these types of projects is usually out of the class as we can often provide the completed project prototypes to these organizations free-of-charge. Of course, this sort of activity is also made possible by the support of other generous donors.

Please also realize that this is an undergraduate class. We believe that what we do is important and that the educational mission benefits our students, their future employers, our society, and the world. We hope that our partners also benefit by contact with these extraodinary young people and that they believe in the mission. Sometimes projects are successful in that a product or result is delivered as hoped at the start. Sometimes everyone gets experience. We cannot promise that external mentors or benefactors will benefit directly. If you have a project that is well suited to an academic research setting and that must come through with certain deliverables, we would be happy to facilitate contact with the appropriate faculty to form a sponsored research agreement.

Contact and Getting Started

Contact Professor Carney by email at carney@illinois.edu. Contact is welcome anytime, though ideally enough time before the start of the semester will be allowed to pass a problem statement back and forth a couple of times. This usually means two or three weeks before the start of the semester. The class meets the first Wednesday of the semester. The academic calendar is available here. Early contact never hurts. For maximum efficiency, please email Prof. Carney with the following information:

Ongoing contact

If your problem is taken up, we will work with you to set up a contact schedule that you are comfortable with. If you have time to very actively mentor the students, a weekly meeting by email, phone or even in person may be appropriate. If you are busy or such regular contact just isn't called for, less frequent meetings or just regular updates may be arranged. Regardless of external mentor participation level, every group will be assigned an internal mentor (a TA) who will ensure that the academic aims of the course are being met. We encourage mentors to attend demonstrations and presentations at the end of the semester if reasonably possible.

If your problem is not taken up one semester, we can carry it over to the next if you like. We can also work with you to more carefully state and scope the problem to attract participation. Our students are deeply intellectually ambitious. They are often up for changing the world.

Historic projects

The course has used an online project management and archiving system since 1999.

Hall of Fame

Each semester, we give out awards to students that have performed exceptionally well. A list if these award winners and links to their project details are available in the "Hall of Fame."

Search all Student Projects

The Senior Design class of the ECE department has all of its projects posted online. The database includes details such as proposals, presentation slides, final papers, and student resumes. With 100 students and 40 projects in a typical semester, it has become a worthwhile recruiting tool.

Course Mechanics Overview

The Senior Projects Class (ECE445) is a 2 hour required laboratory class for electrical engineers where the students 'engineer' a project. We typically have 100 students (40 projects) per term.

A major course objective is to offer the students a guided design experience which involves all the issues of design, assembly, and test of hardware. We work to develop written communication skills through a written proposal, design schematics, and a final report. Oral skills are developed through weekly meetings with TAs, the informal design review, an oral demonstration, and a formal presentation. Up until this point in their. In addition we teach the students to follow a schedule, to keep track of cost, and to deliver on time.

Schedule

The semester begins over the 1st 10 days on 'identifying a project' and picking a partner (or 2 in some cases). A week later, the project 'PROPOSAL' is due and 10 days later, an informal design review is held for each project with the course Director, Graduate Student Teaching Assistant, and another student team as a PEER reviewer. Each team must peer review another. Following this, the students enter the assembly, build, and test phase of the project (9-10 weeks). The last week of the semester involves a 'DEMONSTRATION' and 'PRESENTATION' (30 minutes each), along with a 'FINAL REPORT', which will be submitted electronically. As part of the exercise, students are encouraged to be ambitious, but for overly ambitious projects we bracket a section to be graded.

Resources

Our resources include people and equipment. In addition to myself, we have 5 graduate students with varied backgrounds who each take on an average of 12-15 projects for weekly team meetings. The graduate students gain management experience in this role. We have 90 faculty members in ECE, but a dedicated set of 8-10 advisors are identified for the students. These advisors act as discipline specific mentors or advisors, especially early in the project formation when students are focusing on the specific problem formulation. We have a dedicated laboratory which they have access to 24 hours a day. The environment is informal so the students feel comfortable as they put in long hours on their projects. We have an electronics shop which has been stocked with many parts from generous donors. We have an electronic method for the students to order parts from the shop. We have a budget of ~$40 per project for those parts not available in the shop which can be ordered from our own store or business office located in Everitt Lab.

On-line Projects Database

Details about the course can be found on the home page. All projects are posted on-line in the projects database.

Selection of Projects

How do the students pick projects? The first two class meetings, we overwhelm the students with our ideas. We invite the advising faculty to provide ideas in power, microprocessors, biomems, remote sensing, and so on. In fact, about 1/3 of the projects are actually implemented in research laboratories in microelectronics laboratory, biomems laboratory, or other ECE research laboratories. The students are told to choose a project by day 10, or one will be provided to them. They all come up with one of their own, but with lots of advice on how to follow the project requirements.

Motivation

Motivation? My motivation as the course director is to provide the greatest opportunity for the students and to give them a practical experience. The students become motivated simply by being linked to a real customer. I also believe this is a great way for industrial sponsors to work with students who will be graduating.

The interaction offers an experience which may lead to employment. The company sponsor may actually get some real problems solved! Institutions who have in-house component availability and can supply those components to the students are most welcomed. The course is a real fire drill from the standpoint that all activities must be completed in a semester and parts accessibility is a real key to project success. We have a firm schedule and we stick to it. With the gift funds, we can order parts which are in stock with suppliers and use expedient delivery services when necessary.

Deliverables

The project product in this case is the final report. Final reports for the class will be made available electronically to all, so confidentiality is not normally part of the deal. The reports are used as an archive for the following class to grow from and for industry recruiters to search. The final reports can lack specific information, and not be published if that is desired on the part of a project sponsor.

Wrap-up

As you may well imagine, the process we have set up to manage and funnel resources directly to students is most efficient . The gift funds for this activity are not burdened by the University. A project will be managed just like the rest of the projects in the class. Sponsors are invited to participate in reviews, as they wish, and to make input during those reviews. Review dates are posted on our calendar each term, and specific team review times are formulated and available at least 2 days before the actual reviews. A project offered does not guarantee it will be performed a given semester as we still leave it to the students to select a project they are interested in. In this case, no funds will be spent or redirected, but the project will be offered the following term, unless otherwise specified or modified by the sponsor.

Thank you for your interest and support!



Sincerely,

Prof. P Scott Carney and Prof. Gary R. Swenson

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

Isaac Brorson, Stefan Sokolowski, Mitchell Stermer

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

Featured Project

Multipurpose Temperature Controlled Chamber (for Consumer Applications)

#TEAM MEMBERS:

Stefan Sokolowski (stefans2)

Mitchell Stermer (stermer2)

Isaac Brorson (brorson2)

#PROBLEM:

Have you ever put a drink in the freezer to make it cool down faster, only to forget about it and later find it exploded and frozen?

Or have you wanted to cook a steak, but forgotten to move it from the freezer to the refrigerator the previous day?

Finally, has there ever been a time when you set food out overnight in order to prepare it for the next day but only to find that it didn’t thaw as expected?

We have done all of these things plus more and have always wished there were a smart device that could quickly cool or warm food without freezing or cooking it.

#SOLUTION:

Our project would be a programmable temperature controlled chamber which allows a user to set the temperature curve of a food item they are planning on consuming in the near future. This device would be able to quickly heat or cool food to a desired temperature, then hold it at that temperature until the user is ready to use the food. The way someone would use this device would start by placing their food item in the device's insulative chamber and closing the door. The user interface would present the user with a variety of options: standard heating or cooling presets for common food items, temperature set and hold, or the ability to set a detailed temperature curve.

If you want to cool a drink to just above freezing, you would select the corresponding menu option, and this device will lower the temperature of its chamber to well below freezing, then slowly raise its temperature to ensure the drink doesn't freeze.

If you select the menu option to thaw a steak, this device will raise the temperature of the chamber to just below the point at which meat begins to cook, (roughly 105 degrees F) then slowly lower the temperature towards room temperature.

This device could also be used for applications outside of cuisine. Say you’re running an experiment to test the capacity of a battery at different temperatures. You could set a temperature curve to visit several different temperatures and hold each one as your battery capacity tester runs its tests. This would allow you to automate an experiment that would otherwise require intermittent attention over the span of multiple hours.

There are temperature controlled chambers on the market, but they’re all exorbitantly expensive and large for a household kitchen. We want to make a device that could sit on a countertop and be affordable to anyone who has the budget for other standard kitchen appliances.

![pic](https://i.imgur.com/HJiCQsN.png)

#POWER

We plan to use a dual output DC power supply such as the RD-125B[1] to power both our digital electronics and the high power heating and cooling elements. This power supply would be plugged directly into an outlet using a 120V plug, and would create 5V and 24V DC outputs. According to its datasheet[1], the RD-125B’s 24V output is rated to supply 4.6A, which equates to just over 110W. Based on our research of thermoelectric coolers and heating elements, we think this should be plenty of power for our application.The RD-125B’s 5V output is rated to supply far more power than our 5V electronics could possibly draw.

#MECHANICAL DESIGN

In order to reach temperatures below freezing with thermoelectric coolers, we’ll need to thermally insulate the chamber very well. Since this insulation needs to be able to withstand the heat produced by the heating elements, we landed on Kaowool. This ceramic wool insulates very well while also being rated to over 1000℃[2].

Since our device is intended for food applications, it’s important for our temperature controlled chamber to be waterproof and food safe. For this reason, we plan to purchase an off-the-shelf cooking pot such as this one[3]. By fitting a smaller pot inside of a slightly larger pot, we can create an affordable and convenient way to insulate our chamber. We can fit the gap between the pots with Kaowool insulation, and use the larger pot’s lid with Kaowool in it to seal the top.

To heat the chamber, we plan to wrap a resistive heating element (such as nichrome wire) around the inner chamber. Since we plan to use an electrically conductive pot for our inner chamber, we’ll need to insulate the heating element from it to prevent shorting. This can be done with Kapton tape, which can withstand temperatures ranging from -269℃ to 400℃[4].

To cool the chamber, we plan to use thermoelectric cooling modules. These require a good thermal pathway to work well, so we’ll need to use a material with high thermal conductivity to mount them to the chamber wall. We plan to ask the machine shop to machine us aluminum mounts which match the curved outside surface of the pot composing the chamber to the flat faces of the thermoelectric cooling elements. Additionally, we’ll use thermal grease to reduce the thermal resistance of the junctions. The thermoelectric coolers will require rectangular holes cut through the wall of the outer pot so they can pump heat to outside of the device.

We plan to mount our circuit board and the user interface electronics in an E-box attached to the side of the outer pot. We can use standoff rods to ensure the electronics don’t get heated or cooled too much from being close to the chamber, though we expect that our thermal insulation will be good enough for that not to be a concern.

#HEATING SUBSYSTEM

As mentioned in mechanical design, we plan to use a resistive heating element to heat the chamber. This will be powered by the higher voltage DC power rail produced by the power supply, which is 24V for the RD-125B. We'll use a solid state switch to control the current through the heating element. This allows us to control its power using PWM, which is essential for ensuring the chamber temperature remains below a certain prescribed level.

The simplest and most cost effective switching device would be an N-channel power MOSFET such as the Taiwan Semiconductor TSM170N06CH[5].

#COOLING SUBSYSTEM

We plan to use thermoelectric (Peltier) coolers to provide the cooling. These work as heat pumps, so we’ll need heat sinks and cooling fans to dissipate the heat they produce. The thermoelectric coolers and fans will be run off of the same higher voltage DC that powers the heating element.

We want to have the option to run the thermoelectric coolers in reverse while the chamber is heating to prevent their heat sinks from cooling down the chamber. To do this we’ll need to power the thermoelectric coolers through an H-bridge so that we can reverse their polarities. The H-bridge can be composed of two N-channel MOSFETs such as the one mentioned above[5], and two P-channel MOSFETs such as the Rectron Semiconductor RM15P55LD[6]. The H bridge can be controlled by the STM32 microcontroller, allowing us to use PWM to vary the power supplied to the thermoelectric coolers. We may or may not need gate drivers for the H-bridge. Gate drivers are necessary for a fast switching rate, but our application doesn’t require high frequency PWM.

#TEMPERATURE MEASUREMENT SUBSYSTEMS

To be as precise as possible, we want distinct temperature sensors for measuring the temperature of the air in the chamber and the temperature of the item being warmed or cooled. Measuring the temperature of the food is made difficult due to many food items having insulative packaging. (Glass bottles, styrofoam containers, etc...) Since we want our device to work for as wide of a range of food items as possible, we plan to give the user the option to select from multiple different interchangeable food temperature probes. Temperature sensing probes could include a meat thermometer, a flat metallic probe that could be placed on frozen meat, or a ring shaped thermometer that could go around a bottle or can.

Temperature sensing (thermocouple / thermopile) may require some basic analog electronics, such as an op amp to amplify the small voltage produced by a thermocouple.

#USER INTERFACE SUBSYSTEM

We plan to use an STM32 microcontroller, for our use a STM32F103C8T6 would probably suffice with IO and processing power, but more capable F4’s might be considered if we add more sensors. The microcontroller and user interface will require logic level voltage DC.

We would most likely use an I2C enabled LCD display as well as a bright, external RGB LED in order to show the user what state the machine is in from a distance. We plan to use a push button rotary encoder to allow the user to interact with the device, in addition to an ON/OFF switch and a "cancel" button. User feedback should be fairly simple and if time allows, we might consider connecting the device to an external service to send users notification as to the status of their heating/cooling cycle.

The user interface screen will have multiple interactive menus: one to select the behavior mode of the device, one to set temperature and time values, one to show a temperature curve, and one to be displayed while the device is operating.

#CHALLENGES & CONSIDERATIONS:

- Everything inside the chamber will need to be able to withstand the full range of temperature.

- Electronics will need to be very well thermally insulated from the chamber if we want to use it as an oven.

- Since thermopiles operate off of a temperature gradient, they require a stable case temperature. This means we'll need to keep the thermocouple in a temperature controlled environment.

- The chamber should ideally be made watertight for the case of a spill or leak.

- When making the mechanical design, we'll need to keep in mind how different materials expand / contract at different rates when they're heated / cooled.

#CRITERION FOR SUCCESS:

- Inside of the chamber should be able to reach at a low end 0 degrees Celsius and at a high end 40 degrees Celsius.

- Be able to hold temperature to within +-5 degrees Celsius of target temperature.

- User has the ability to set target temperature, heating/cooling curve and max/min temperature allowances through GUI on an LCD display.

- Display of current temperature, and possibly a plot of the temperature vs. time graph.

- Ability to select the behavior of the device from a provided menu of presets for different foods.

- (Stretch Goal) We could possibly include multiple different methods to measure food temperature in addition to the ambient temperature. (Stainless steel probe to measure the internal temperature of meats, thermocouple for bottles and containers)

[1] Power Supply:

https://www.mouser.com/datasheet/2/260/RD_125_SPEC-1511572.pdf

[2] Kaowool:

https://www.morganthermalceramics.com/media/llhhadih/5-14-205_kaowoolblankets_072018.pdf

[3] Aluminum pot: https://www.amazon.com/Winco-Winware-Aluminum-Stockpot-12-Quart/dp/B001CHMIQ4/ref=sr_1_10?crid=1VECOQHCN2UC2&keywords=aluminum%2Bpot&qid=1706684643&sprefix=aluminum%2Bpot%2Caps%2C93&sr=8-10&th=1

[4] Kapton tape:

https://www.dupont.com/electronics-industrial/kapton-hn.html#:~:text=Kapton%C2%AE%20HN%20has%20been,C%20(752%C2%B0F).

[5] N channel MOSFET:

https://services.ts.com.tw/storage/resources/datasheet/TSM170N06CH_A2211.pdf

[6] P channel MOSFET:

https://www.mouser.com/datasheet/2/345/rm15p55ld-1396325.pdf

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