Lif: A CAD Model

A continuation of prototyping an IoT device that promotes a happy, healthy house plant

Sara Gustafson
4 min readOct 22, 2020

Are you a plant-owner, plant-lover, or just curious about how to keep your plants alive and healthy for more than a week? If you answered yes, head on over to my Medium article where I explain the motivation and design for Lif: an IoT plant wearable. If you have already read that and are interested in how I prototyped Lif in CAD, you are in the right place. Let’s dig in.

Design

To give a quick overview, Lif has two user groups: the plant itself and the human that interacts with the device and maintains the plant’s health. The device is stuck into the plant soil to measure vitals, and the screen interface will alert the human when the plant needs water, food, or sun. The human can also monitor the plant’s health from a mobile device using the Lif application.

In my analog cardboard prototype, I was able to test the device on a few house plants and found that it could be desirable and viable for both users. Though, the feasibility of the device remains uncertain. With this important consideration still in question, I prototyped Lif in a computer-aided design (CAD) program called OnShape. This allowed me to test whether the design and form are achievable under 3D modeling constraints. If possible, Lif would be a step closer to being feasible for both plants and humans. Successfully designing Lif in CAD would allow the manufacturing process to be sped up. However, Lif's complex technical aspects would need to be straightened out before determining it as a fully feasible product.

Prototype

Despite the technical challenges that come with realistically crafting Lif, creating the CAD prototype came relatively easy. Due to the basic shapes and functions that it took to put the CAD model together, I took a few extra steps to make the model look more realistic.

Basic view of Lif CAD model

Using the offset surface feature in OnShape, I made Lif's top face have a screen element so that the prototype looks interactive. This enhances the comparison to what the actual Lif product may look like. Additionally, most leaves are not fully horizontal in orientation, so I added a bend in the prototype to simulate how a real leaf may actually be oriented. This feature was achieved using the extrude cut function on OnShape.

Bend view of Lif CAD model

Finally, the Lif CAD model's last important feature is the hole in the stem that gets placed into the soil.

Bottom view of Lif CAD model

Here you can see a hole in the bottom of the rod at the end of Lif. Constructed using the revolve feature in OnShape, the hole was put in place to add extra sensors to the stem's end. The inside of the prong will gather more soil and might be able to detect moisture and, therefore, health more effectively.

Analysis

Though I believe Lif's CAD design showcases a successful 3D prototype, I know that this would need to be printed and tested on both user groups. Without this knowledge, I cannot fully determine the design's desirability, viability, and feasibility. However, after crafting Lif in CAD, I am more confident that the design is feasible in this particular use case. Again, as mentioned above, I cannot fully comprehend the technical undertakings needed to make this product interactive successfully, further detracting from feasibility.

Despite Lif’s ambiguous usability and feasibility, I could have chosen more complex and efficient ways to create the Lif CAD model. I found myself relying on functions that I know would work rather than branching out to new, possibly more effective tools. I may opt for a larger (in diameter) prong in terms of the actual Lif design, as I am unsure if the one I have currently modeled would hold up in soil for an extended period of time.

Overall, I found the process of turning an analog prototype into a CAD model exciting and satisfying. I anticipate using CAD in the future and am eager to learn more about the tools that may uplift my future prototyping endeavors.

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