College - Author 1

College of Engineering

Department - Author 1

Biomedical Engineering Department

Degree Name - Author 1

BS in Biomedical Engineering

College - Author 2

College of Engineering

Department - Author 2

Biomedical Engineering Department

Degree - Author 2

BS in Biomedical Engineering

College - Author 3

College of Engineering

Department - Author 3

Biomedical Engineering Department

Degree - Author 3

BS in Biomedical Engineering



Primary Advisor

Christopher Heylman, College of Engineering, Biomedical Engineering Department


FeverDots are wearable temperature sensitive stickers that change color from black to pink at 99°F when placed on the temple or forehead. The objective of this project was to develop an efficient manufacturing method for FeverDots, and manufacture a device along with it. To create the FeverDots manufacturing device, the full design process was executed. The team went through a thorough ideation phase before ultimately defining and specifying the scope of the project.

The key customer requirements of this device include that it is lightweight, portable, durable, simple to assemble, easy to use, and able to generate uniform ink and force distribution. One additional requirement from the sponsors was feedback from human use of FeverDots. The key requirements were analyzed and translated into quantifiable engineering specifications. The lightweight and portable requirement is quantified by a 30 lb maximum weight measurement. Durability was also quantified by a maximum total length of cracking in the wood set at 10 inches. A maximum number of 10 steps to go through a full cycle of stamping was set to quantify simple assembly. Ease of use was quantified with a spec of 27 ± 4N required to start the motion of the device. Finally, the device’s ability to generate uniform ink and force distribution was quantified with a 0.015 ± 0.002 g/in2 measurement for dry weight of ink and a minimum of 85% of the sticker paper receiving a uniform application of force per cycle.

An initial conceptual model was developed to test out the initial mechanical ideas; as these ideas were further defined and developed, the final design was selected. The transition from conceptual to final design occurred with a central focus on obtaining equal force and ink distribution. Four total iterations of the prototype were created throughout the life of the project, including the initial and final prototypes. The various iterations were made to fine-tune the ink stamping mechanism and the interactions between assembly pieces.

The team conducted 7 different tests to analyze if it met the specified metrics outlined above. These tests were for: weight and portability, durability, simple assembly, dry weight specification for ink, ink distribution, force uniformity, and minimum force. The purpose of the Weight and Portability test was to identify if the device was not excessively heavy. Next, the Durability test was designed to assess if the parts would be able to remain assembled during stamping, and the Simple Assembly test analyzed if the device requires too many operational steps for use. Also, the Dry Weight Specification of Ink Test allowed the team to observe if the device could apply the correct amount of ink onto the substrate, while the Ink Distribution Test evaluated how well the ink spread across the substrate. Similarly, the Force Uniformity Test noted how force was applied throughout the lid of the device. Lastly, the Minimum Force Test determined if the force threshold to move the device was feasible. To gain data on the human use of FeverDots, a human use study was conducted; survey results were analyzed and presented to our sponsors.

The device achieved uniform force as it met the specification of 85% during the force uniformity test. Additionally, it met the specifications for simple assembly and easy to use as the number of operational steps include only 9 and that it showed to only require a range of 23 N to 31 N to be able to move the lid, respectively. It also passed the portability test as its weight was only 12.2 lbs.

However, it failed the customer requirement of generating uniform ink application. This was revealed as it was unable to meet the specifications of 0.015 g/in² for the dry weight of the ink and 85% of the sticker paper area covered with ink. Lastly, it also failed the durability test as the total crack length summed to over 10 inches.