Skills
Haptics, Fabrication, Arduino
Collaborative Project
Smart Lids: Drink Tampering Protection
Lit Lids device prevents drink tampering by providing a physical barrier between the drink and the outside world. Each Lid is connected to a smart bracelet that serves to both safely 'unlock' the Lid and alert the user when a different individual has removed their Lid. This gives the user freedom to walk away from their drinks without fear.
When the Lid is removed by anyone besides the user, the bracelet alerts the user via haptic and visual feedback that their drink is no longer safe. In addition, upon returning to their drink, all the lights on the Lid glow red in warning and remain red until the user taps their bracelet on it to reset it.
Vision
Drink tampering is a prevalent problem and starts on average beginning in college. In a study with 956 participants, it was discovered that 44% of men and 56% of women had their drink spiked at least once*. Many existing products focus on testing drinks with single-use chemical strips, leading to both an unsustainable and high-friction user experience.
We wanted to create a product that felt seamless and natural. Lit Lids was created to be a reusable solution that provides real-time feedback to prevent any type of drink tampering. The wearable device connected to each Lid becomes an extension of the user's body and allows them to enjoy social gatherings with minimal mental load. Our vision was to create a simple, yet effective solution that allows people to enjoy themselves to the fullest when out.
*American Addiction Centers
Process Flow
1. Lid has a motion sensor placed on the bottom that allows it to identify when it has been placed on a cup. The LED lights on the Lid turn green to provide feedback to the user that it has turned on.
2. There is an RFID inside the Lid and bracelet that serves to identify them. The HC-05 bluetooth module serves as a communication between the bracelet and the Lid. When the user is within hands distance of their drink, the Lid indicates that the drink is safe.
3. When the user is out of range, the Lid goes from SAFE mode to ALERT mode.
If someone else removes the lid, the bluetooth module sends a signal to the bracelet. Vibration motors and LEDs are activated within the bracelet to indicate to the user that their drink has been touched.
4. Else, the lid LEDs remains green and user is able to return and remove LID. Bluetooth module communicates proximity and RFID is used to confirm identity.
The second form of communication between the Lid and the bracelet is via RFIDs. The bracelet contains the RFID and the Lid contains the RFID reader. The only way to turn the LEDs on the Lid off is by tapping the bracelet on the Lid. The RFID is ideal for this because it needs to be flush against the Lid to turn off. I intentionally opted to add this layer of friction to ensure that the user is aware and consciously choosing to turn the lights off on their Lid. Since this is a scenario of potential danger, requiring more steps to deactivate the Lid draws the user's attention to their cup and allows them to more consciously make decisions.
We chose to also add an RFID identification option beyond the HC-05 identification option because there were a few times that we found that despite the user holding the bracelet in their hand, the Lid and the bracelet had difficulty communicating, and thus we wanted a manual option.
In a world where it's common to have a Lit Lid, we also wanted to prevent the scenario from accidentally taking off someone else's drink Lid. To combat this, if the RFID scanned is not connected to a Lid, only the middle LED will flash red to signal that it's not the right cup. However, if the correct RFID is scanned, the middle LED will flash green.
Future Iterations
There are a few ways that this product could be improved further in the future.
1. More gender-neutral wrist-wearable. We opted for the bow scrunchie because we only had access to an Arduino Uno and needed a more roomy wristband that allowed us to hide the Uno within it. In the future, we would use a smaller microcontroller.
2. Lids with names on it- currently there is only one design for the Lid. In a world where more people own this device, we want to prevent people from accidentally triggering the device alarm by removing the wrong Lid.
Bracelet Sketches
Lid Sketches
Design
Bracelet
When designing, we opted for a wearable device rather than a phone alert because we wanted the product to be in the user's peripheral. A wearable device that physically vibrates and flashes red lights when there is danger skips the 'middle man' and gives a direct warning. Haptic alerts allow the user to be screen-free and fully immerse themselves in their setting.
The wrist was also chosen over another location on the body (ie. along the back or around the neck) because of the ease of visibility and access. Since it is common for all genders and ages to wear a device around their wrist, the product would be both discreet and accessible. For this project, we only had access to an Arduino, so we opted to use a larger scrunchie to provide enough room to hide the wiring and the microcontroller.
Lid
The Lid itself has a ring of LED lights at the top to signal whether it is 'safe' or 'unsafe'. The LEDs at the top of the Lid remain off while it is safe. However, if someone besides the owner of the Lid removes it, the LEDs are triggered and flash red. This is a universal signal to everyone around that the drink is no longer safe.
We chose a visual queue on the Lid as well to provide an additional layer of security beyond the bracelet. For any reason, if the owner of the bracelet isn't aware of their bracelet alerts, people in their surroundings can look out for them and protect them. The user can turn the LEDs off the Lid by tapping their bracelet on it.
Hardware + Software
In this project, I owned the design decisions and the fabrication. As a team, we worked collaboratively on the Arduino code.
Both the Lid and the wearable interface are 3D printed. I attached a motion sensor to the underside rim to determine when the Lid is on or off the cup. There are two main ways that information is passed from the Lid to the bracelet.
The first is via HC-05 Bluetooth module. The Bluetooth is used to calculate the distance between the Lid and the bracelet to determine whether the user or someone else took the Lid off. If the Lid is taken off within 20 centimeters of the bracelet, it is considered safe. Else, both the Lid and the bracelet are triggered to go into alert mode.