Mechanical engineering graduate student Juan Espinoza has been around agriculture his whole life. While growing up in the small city of Shafter, just 18 miles northwest of Bakersfield, he recalls his parents picking crops and flowers year-round.
“My parents immigrated from Mexico to California in the late ’90s,” Espinoza said. “At first, they did not have any formal education or training, so the only work opportunities available at the time was in the fields.”
His parents, who worked as farm laborers for a combined 20 years, will see decades of sacrifice come to fruition when Espinoza graduates with his master’s degree at the Lyles College of Engineering Fall Convocation at 9:30 a.m., Friday, Dec. 19, at Fresno State’s Satellite Student Union. Espinoza was selected to be the student speaker and will join over 130 other graduates earning their bachelor’s and master’s degrees.
Wanting their children to learn the value of a dollar, and hoping to motivate them to pursue higher education, Espinoza’s parents encouraged him and his siblings to get their worker’s permits and spend their summer breaks working in the fields, as well.
Espinoza first worked in the fields the summer after his freshmen year of high school. At 15, he experienced firsthand the intensity and oftentimes backbreaking work of farmworkers who worked through the summer heat. He returned to the fields the next few summers.
Today, Espinoza still spends a lot of time in the fields – now at Fresno State’s on-campus orchard – but his purpose is different.
The future of agriculture
During his time as a graduate student, Espinoza has focused much of his work on researching and building the citrus harvester project – a robot that can harvest citrus, while still retaining the quality of the fruit. The citrus harvester is made up of a couple of key components, including the gripper and the cutter, which is made specifically for citrus.
“Citrus harvesting is a very delicate process,” Espinoza said. “You can’t just pull citrus off the stem. Tearing the fruit from the tree altogether, without a precise cut, leaves an open cavity at the top of the citrus, which leads to rapid decay. So the traditional practice is to cut it with a special pair of harvesting shears precisely at the stem-calyx interface. The citrus harvester project automates this process, giving farmers a more precise cut, while also helping to fill a gap in labor shortages.”
Dr. Alaeddin Bani Milhim, assistant professor of mechanical engineering at Fresno State, first introduced Espinoza to the idea of the citrus harvester project through his advanced mechatronics course. With an idea and open canvas, it was up to Espinoza and his teammates to bring the robot from conception to prototype to reality. The project is made possible through funding from the F3 (Farms Food Future) Initiative, which is committed to developing a skilled workforce pipeline for sustainable food production and manufacturing.
“Juan joined my research group in February 2025 and immediately demonstrated strong initiative and technical ability,” Milhim said. “Since then, he has led the mechanical design of the harvesting end-effector and its field evaluation, contributing ideas that significantly improved its performance and reliability. His commitment, attention to detail and rapid prototyping drive – as well as willingness to support and guide other team members – have been critical to the project’s success. Juan is a great example of how dedication and engagement in graduate school can really elevate a student’s skills and professional maturity.”
In many ways, Espinoza believes his journey has come full circle – from working in the fields to now contributing to the future of agriculture.
“I feel a great amount of pride being able to give back to the industry that got me to where I am today,” Espinoza said. “Our agricultural farmlands have provided me with a roof over my head and an education. Hopefully, through this project, we can create a product that can help farmers fill labor shortages, but also help to alleviate the difficult labor that farmworkers ultimately have to do.”
A provisional patent application for the project has been filed, and the project team is continuing the next phase of development.
“We started with the end effector, which is essentially the hand of the robotic arm, but we knew we needed more than just the gripper and the cutter mechanism,” Espinoza said. “Now we have more subsystems in place to make it a complete harvester top-to-bottom, including the robotic arm, the vision system, and the mobile platform, which is the biggest piece of equipment we’ve bought to date. It’s an awesome machine. We have all the pieces and now we just need to integrate them.”
Espinoza and his teammates will test the completed project in February. After Espinoza graduates, he will step away from the development side of the project, but will continue in an advisory and mentorship role as a new group of students take the reins.
“We’ve developed the harvest project so much over these past two years that it has become my life’s work in a way,” Espinoza said. “It’s the biggest, most important project that I’ve worked on personally, and I want to be here for the whole process. I want to see it through.”
From Bakersfield to Fresno
It was initially Espinoza’s love of customizing vehicles that inspired his journey into mechanical engineering. In high school, he was part of “Project Lead the Way,” a career readiness program that prepares students for careers in STEM (science, technology, engineering and math).
“During my senior year of high school, our school took us on a tour of Fresno State. It was my first time visiting, and I remember just immediately falling in love with the campus,” Espinoza said. “I fell in love with the engineering labs, the fancy equipment and everything the engineering program was doing. That was my first memory of Fresno State.”
Although Fresno State interested him, Espinoza enrolled at CSU Bakersfield following his senior year of high school in order to save money and stay closer to home. However, he never lost sight of his big picture dreams to attend Fresno State. Soon after graduating in December 2023 with his bachelor’s degree in engineering from CSU Bakersfield, Espinoza immediately began the mechanical engineering master’s program in January 2024 at Fresno State, where he hoped to expand his knowledge and sharpen his skillset further before entering the professional world.
After graduating, Espinoza will continue his relationship with the F3 Initiative and will work closely with the organization on a range of projects that help bring automation to agriculture. As he steps into his new role, Espinoza remains grateful for the education he received at Fresno State.
“Fresno State met all my expectations,” Espinoza said. “The small class sizes allowed me to have a more personal connection with faculty, who are really passionate about what they do. They prepared me well, and I’m grateful to have been able to learn from them. Coming to Fresno State for my master’s degree is the best decision I’ve ever made.”
