Finally, presenting the Dryinator — the ultimate smart and modern solution for all your clothes drying needs!

Features

Main air inlet 

Aluminum poles were used to hang the shirt during drying, chosen specifically for their lightweight nature. This makes the dryer easier and more comfortable to handle, reducing physical strain from lifting heavier materials.

Additionally, small holes were drilled into the poles to create targeted air outlets. These are strategically positioned to direct airflow to areas where multiple fabric seams meet, which typically take longer to dry.

Air Spout

Two aluminum poles are connected using a T-shaped connector, which serves as the main air outlet, channeling airflow directly into the shirt from the top. This connector is designed to fit snugly into the shirt sleeves while also extending far enough into the shirt to minimize air leakage and ensure efficient drying.

Aluminum Rack

To enhance the overall stability of our design, the rack is constructed using sturdy aluminum profiles known for their strength and durability. This material not only ensures structural integrity but also supports the combined weight of the aluminum poles and wet clothes without bending or wobbling.

For additional balance, we incorporated supportive legs into the base of the rack, preventing tipping and ensuring it remains steady even when fully loaded. The rack stands at a comfortable height of 1 meter—ergonomically ideal for users of all heights, eliminating the need to bend down or stretch uncomfortably while hanging or removing clothes.

The compact yet stable design also allows the rack to be conveniently placed indoors, on balconies, or in laundry areas, making it both space-efficient and user-friendly.

Load sensors

There are two load sensors on the rack, one at each end of the pole. When the pole with the garment is placed on the rack, it is placed in such a way that it only has contact with the spacers of both load sensors, and does not have contact with any other part of the frame. This way, the only forces acting on the pole with the garment is its own weight (downwards) and the two normal contact forces between the load sensor and pole (upwards). Thanks to translational equilibrium vertically, the weight of the pole with the garment is equal in magnitude to the sum of the 2 normal contact forces. Since the load sensors are tared with the empty pole placed on them, and their calibration factor already takes into account the gravitational constant, the mass of the shirt is obtained from the sum of the 2 load sensor readings.

Mechanisms

Auto on

The auto-on function was introduced to simplify the user experience by eliminating the hassle of having to push any buttons while already handling a load of laundry. When a mass of more than 50g is detected to have been placed on the pole, our device turns on the fans and begins its drying cycle. This mass of 50g was chosen as the threshold as it is far above the instrumental error range (and hence will not accidentally be turned on even when there are no garments placed) but still below the mass of most garments (most T-shirts weigh around 100g dry).

Auto-off

The auto-off function was introduced so that the device does not continue to consume electricity after the garments are already dry. As the garment dries, water leaves the garment in the form of water vapour, hence the mass of the garment steadily decreases. When the garment is dry, the mass of the garment becomes roughly constant, but it still fluctuates within a range of +/- 1.7g from the dry mass of the garment due to the instrumental error from the load sensors. During the drying process, the mass is polled every 15 seconds. Once the mass stabilises for 12 readings, or 3 minutes, the fans are turned off and a tune is played to notify the user that the drying cycle is complete.

Summary of code for Auto-on and Auto-off

Oscillation of shirt

The shirt is oscillated such that this flapping motion pushes away humid air and brings in dry air, leading to faster drying. The shirt is oscillated using 4 alternately pulsing fans on the side rails near the bottom hem of the T-shirt. Placing the fans near the bottom hem generates the largest moment for the same force exerted from the fan since it is the furthest spot from the pivot which is the pole. This placement also helps target more air flow to the bottom hem of the shirt (which usually dries the slowest due to gravity pulling the water content downwards), leading to more even drying.

To maximise the amplitude of oscillations, we aimed to achieve resonance, where the external driving frequency is equal to the natural oscillating frequency of the system of 1.5s. This is done by turning on the frontal fans for 0.75s while the rear fans were off, then turning on the rear fans for 0.75s while the frontal fans were off.

Final product

Time-lapse

Here is a time lapse video of our working product.

We even managed to dry a polyester skirt within 1.5 hrs.

Drying Efficiency

Compared to conventional air-drying (represented by the blue line), our dryer design significantly accelerates the drying process, as indicated by the red line. Based on our testing, a shirt that has been spun in a washing machine is estimated to dry completely within approximately 2.5 hours using our dryer.

Energy Consumption

Source: https://www.ecoflow.com/au/blog/dryer-power-consumption

Our dryer consumes only around 20% of the energy used by conventional dryers, making it an exceptionally energy-efficient and eco-friendly alternative.