On April 22, we mark Earth Day. Here, we feature some work and research on conservation, sustainability and green practices, pioneered by Berkeley’s former and current graduate students.

A Vaccine Refrigerator Powered by the Sun

Photo courtesy of Thomas Walden Levy
Photo courtesy of Thomas Walden Levy

Ph.D. alumnus Steve Lanzisera is a Research Scientist at the Lawrence Berkeley National Laboratory‘s Environmental Energy Technologies Division. Lanzisera earned his degree in Electrical Engineering and Computer Sciences. His most recent project focused on network-embedded sensors to manage energy usage.

He worked with Berkeley Lab’s sun fridge team to design a portable solar-powered refrigerator that can be used to safely deliver vaccines — specifically to developing countries where vaccine access may be limited. Up to 1.5 million children under the age of five die each year from vaccine-preventable diseases like polio and tetanus, according to World Health Organization (WHO) estimates.

The WHO further shows that vaccines often become spoiled en route before being dispensed because of rough transport conditions and excess heat exposure.

“We just haven’t had good technology for delivering vaccines with good temperature management,” Lanzisera told Berkeley Engineering in February.

The cubical-shaped sun fridge is powered by photovoltaic cells (solar panels) and thermo-electric technology is used to freeze the water and keep vaccines cooled (using heat to make cold).

The team is looking at field-testing prototypes in Africa. They aim to place their sun refrigerators in governments and healthcare organizations throughout South Asia and sub-Saharan Africa.

Turning Blue Jeans, Green

Bioengineering graduate student Zach Russ

Each year, 50,000 tons of indigo dye is produced. The majority of that indigo dye is used by jean manufacturers who produce 3 billion pairs annually. However, modern-day “indigo” no longer comes from the plant — a process phased out around 1900 — instead, indigo dye is synthetically manufactured from petroleum.

Production of this synthetic indigo dye also requires the use of another chemical, or reducing agent, which is harmful to the environment. The reducing agent is toxic enough to corrode piping when it’s sent through waste water treatment plants, according to bioengineering graduate student Zach Russ.

This agent is toxic because it contains sulfur and, when reacting with air and water, heats up and releases fumes, Russ explained. Today, Russ is working to keep our blue jeans more environmentally friendly.

Since April 2013, Russ has worked with Berkeley Bioengineering Professor John Dueber on replacing the chemical process used to generate the color indigo, with a process that uses a plant enzyme or bacteria. Bioengineering graduate student Tammy Hsu also joined the project a year ago. “We’ve been managing to dye fabric without introducing any reducing agent into the fabric,” said Russ. “We found a way to use a different enzyme.”

ZachRussIndigoIndigo is naturally produced when a chemical change occurs in indican, a precursor molecule in plant leaves. When plant leaves are crushed, it releases indican from its sugar molecule and creates the chemical reaction that changes green leaves to blue, or indigo.

“We were going into something that hasn’t really been explored much, it’s been exciting,” said Russ. “Hopefully this technology we’re working on will reduce the need for this reducing agent.”