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PASSAGE is a lighting therapy product that recreates the graduation of light and shadow in nature to calibrate our circadian rhythm, boost productivity, and reshape our concept of time.

Academic personal project, 12 weeks, 2017

Redesigned at 2020


Modern life somehow devastated our health and positive lifestyle. The surging consumption of digital technologies leads to severe distortion of our circadian rhythm. The abstract measurement of time --the clock makes us manage our schedules precisely, but on the other hand, deprives our sensation of time.  

Pain Points

The proliferation of screens in our daily life is disruptive to our circadian rhythm, causing insomnia and other severe diseases such as obesity, heart diseases, and cancer.


Working indoors takes up most of our daytime, making us out of sync with natural circadian rhythms. What's more, we usually don't know the amount of time we spend inside because of the lack of experiential cues.


The concept of time is reshaped over time due to the modernized lifestyle. Time is represented by numbers and sometimes by percentages. It is helpful when we need to manage time precisely. Still, on the other hand, it loses the experience of time and distracts us from understanding how much time is passing by visually and physically.


The passage of time is informed by the change of light and shadow and the sun's trajectory in nature. Living in a modern life full of stress and  I find nature is the only way for me to get away from digital fatigue. The interrelationship and change of natural light and shadow not only relax me but also give the clue of how much time is passing by. What's more, spending time outdoor always refreshes my mind and helps me get asleep at night easily. This experience inspired me to rethink how might we understand time and how to manage and make the most of it.

Design concept

The design concept of this project is to recover the experience of time that was once ubiquitous in our lives and use it to augment our sensation of time, calibrate our circadian rhythm, filter the harms and fatigue given by the modern environment, and improve positive mood and mental well-being.

Design Process

The beginning of the design concept was only an ambient light indicating how much daytime is left. It informed people of the process of time passing and helped them form a better understanding of time. During the first phase of ideation, I only related time to light and try to create dynamic movements that remind people of the passage of time.

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Mock-up 1: A round light dimmer that created a radical dynamic movement. The emitting light from the device formed a full illuminant circle on the wall at the beginning of the day and gradually dimmed by blocking the beams emitting from the circumference until it fully closed at the end of the day.

Mock-up 2: A slim light bar that created a linear movement. The baffle gradually moved from left to right to reduce the emitting area according to the time of day.


However, according to feedback from users and other designers in design reviews, I learned that people from different cultural backgrounds might perceive time differently.


I dived deeper into different perceptions of time according to the cultural background and decided to design a more universally intuitive representation. The concept of having a one-point-light source that simulates the sun's trajectory is one of the best ways to inform the passage of time to most people in the world.


The second most important pivot happened when designing how to cast a "natural" shadow. "Guang Yin" is the old Chinese word of time. It means "light and shadow." Their interrelationship creates movement that was used to measure time in many ancient oriental cultures -- Sundial.


The Sundial is just a very small epitome of light and shadow, The most dramatic and beautiful moments happen in nature. How might we infuse those beautiful moments in the design? How might we bring nature into the product?


I drew elements like hills, waves, and dunes from nature and used grasshoppers to stimulate random forms to represent them. While brainstorming how to materialize the form, I realized using synthetic materials is odds to recreate them. I moved on to experiment with a more natural material -- compound stones.


While the primary concept and form were established, lighting design is left to experiment. I made multiple segments to install in the prototype and brought them to user test.


According to the feedback, direct lighting created the most contrast, but it's not friendly for the users when used in a reading and working environment. Diffused lighting with frost glass is less effective in casting contrast, but it's beneficial in creating ambient and more user-friendly working environments. Diffuse reflection lighting had a similar effect as diffuse lighting with frost glass, but it's visually more even aesthetically pleasing. To create more friendly and adequate lighting, I used Diffuse lighting with frost glass on the moving hand and incorporated another light source between the stone and the back cover to create a more gentle and effective ambient lighting.


While Reshaping the concept of time and calibrating the user's circadian are the primary objectives, improve positive mood and mental well-being is another underlying and essential objective.

According to the research on the psychological impact of color lighting, blue light can help decrease melatonin levels and raise our spirits. Orange light boosts one's concentration, motivation, and creativity. Purple light helps us calm down and reduce emotional and mental stress. Red light stimulates melatonin production and helps us sleep; orange light stimulates creativity, and yellow light promotes optimism and helps us filter out blue light.


As a result, different color lightings are incorporated to improve mood, enhance mental well-being, and boost productivity. I also added white noise to the product to make a more effective ambience.

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Final Design Rendering

The final design prototype was presented in front of the public at the end of the academic term. It successfully told the story that numbers cannot represent time. Time is alive, and it’s always moving. We must feel its changes before we can treasure it.