The University of Arkansas (U of A) has made a significant advancement in agricultural technology with its recent patent for a device known as the “Soft Robotic Gripper for Berry Harvesting.” Indiana-based Anthony Gunderman created this ingenious contraption, which won a U.S. patent last month. He is currently assistant professor in the Department of Mechanical Engineering at University of Arkansas. Yue Chen, a former U of A professor now at Georgia Tech, worked extensively on the project. Jeremy Collins, a mechanical engineer and former undergraduate engineering student from U of A, lent his expertise.
The robotic gripper features three fingers, each composed of a soft, flexible material. This design allows it to firmly yet gently crush delicate blackberries without permanently damaging them. The design is informed by the behavior of tulip flowers, opening and closing as conditions change with the movement of the sun. Gunderman noted, “I was inspired by the way a tulip flower opens and closes when the sunlight hits it.”
Blackberries, one of Arkansas’s largest specialty crops, are worth about $24.3 million a year to the state’s economy. Traditionally, the delicate nature of these fragile berries requires hand-harvesting, which blueberry harvesters are known for. Their fragility presents a challenge in collecting them without destroying their unique form. In recent years a farm labor crisis has developed. A robotic harvester is a potential answer to this critical conundrum.
The primary goal of the multi-institutional research team was to quantify the impact force when harvesting blackberries to avoid bruising fruit. This research lays the foundation for why the soft gripper works so well. Gunderman explained, “When we’re talking about one specific task, it is certainly the case that you could design something that is better than the human hand for that one specific task.” He further elaborated on the variability in berry quality based on the experience of the harvester: “Depending on if you have a brand-new hand harvester or someone who’s been doing it for decades, you will get vastly different berry quality.”
The possible uses of this technology go far beyond agricultural applications. The soft gripper serves as an assistive device to those whose mobility is compromised due to injury or age. Most importantly, it enhances their capacity to execute functions that require a nuanced hand.
Andrea Myers, a recent graduate from U of A, worked on this pioneering project. Renee Threlfall, an associate professor of food science, jumped aboard as well. As a team, they collaborated to improve the engineering and usability of the robotic hand.
Indeed, the American berry market has a coming of age, blossoming into a multi-billion-dollar industry. Innovations such as the soft robotic gripper hold tremendous potential to increase agricultural efficiency and productivity.