WASHINGTON, Sept. 24, 2024 – Seen atop pagodas, inside Buddhist ordination halls, and in royal palaces, the tiered umbrella is one of Thailand's oldest and most sacred ornamental symbols. Constructing one of these ornate pieces, also called chatras, can take master artisans up to six months.
In the Journal of Laser Applications, from AIP Publishing, researchers have demonstrated a technique for constructing seven-tiered umbrellas using high-powered lasers, dramatically reducing the production time. Employing carbon dioxide lasers, they were able to fashion umbrellas from stainless steel in a matter of days while preserving their intricate beauty.
"At present, the craftsmen who make tiered umbrellas have become scarce," said author Pichet Limsuwan. "We hope to show a new way we can help conserve arts and culture in Thailand."
Use of chatras dates to the Dvaravati Kingdom, which ruled what is now modern Thailand 1,400 years ago. Royal chatras come in odd-numbered variations of five-, seven-, and nine-tiered umbrellas that correspond to princes, crown princes, and kings, respectively.
Limsuwan set to work a year ago to better understand the customs surrounding chatras and how they are made. His first months researching the umbrellas included poring over primary historical documents written in Thai and then synthesizing his research into a written history in English — a type of research rare for physicists.
Adorned with ornately patterned brass and often featuring shades made of white silk trimmed with gold and precious gems, the conical chatras hang above sacred places, with each concentric tier wider than those above it.
"A new king will not be able to sit on the throne under the nine-tiered umbrella until the coronation rites are completed," Limsuwan said.
Lasers provide an array of advantages in manufacturing such finely detailed items, including narrow cuts, smooth edges, and the ability to tackle complex shapes.
Brass traditionally used for chatras, however, is highly reflective and poorly suited to laser cutting. As a workaround, the team used stainless steel. To achieve the characteristic golden color, they deposited titanium nitride onto the steel using electric arcs in vacuum chambers.
This approach cuts the six-month timeframe for making one umbrella into roughly 113 hours. While much of the process is automated, hand-drawn art can be easily incorporated by using common tools in laser manufacturing.
The group provides many of the technical details for anyone with the necessary equipment to make umbrellas on their own, ranging from vacuum and electricity settings to deposit titanium nitride to expected production times for each part.
"Thailand is a country with a lot of arts and culture," Limsuwan said. "Tiered umbrellas are just an example of Thailand's arts, culture, and religions. I think that the next projects will be related to other facets of Thailand's arts, culture, and religions."
