Agriculture is one of the industries that is getting increasingly affected by robotics, which totally makes sense, as farmers around the world face human labor shortages and also rising labor costs. For some crops, labor accounts for almost 50% of production expenses.
What's more, harvesting fruits and vegetables is especially challenging because some plants, such as strawberries, raspberries, and avocados, have a very short harvesting period and bruise easily. As a result, farmers often lose up to 25% of their crops. Researchers at West Virginia University (WVU) have developed a soft robotic hand that could solve most of these problems by harvesting delicate fruits efficiently while minimizing waste.
Agricultural robots have been around for a while, but most of them are quite rigid and bulky, have a hard grip, and lack tactile sensors. They do a good job picking up apples or citrus, but struggle with more delicate produce.
The research group at WVU is called the Robiotics Lab, and its members focus on developing robots that mimic animal movement. The robotic hand they have been working on is not quite the rigid metallic claw we might imagine when thinking about robots. It draws inspiration from starfish, and features soft fingers made of silicone and polyurethane. The device still somewhat resembles a human hand, with five flexible fingers designed to gently pick fruits.
The new robotic hand is equipped with a miniature camera that can assess the ripeness of fruit, which we’ve seen before in some agricultural robots. The problem with this technology is that visual inspection is not always accurate. The ripeness of certain fruits, such as avocados, is difficult to judge visually, so people usually gently squeeze them. This method is pretty reliable and simple, but teaching a robot to do it was one of the key challenges for the scientists.
As a result, the robotic fingers are not just soft and flexible, but also feature special sensors that can assess the ripeness of fruit through touch. These sensors allow the robot to squeeze the fruit just enough to determine its firmness without squishing it. Another useful feature is that the sensors can detect whether the grip is secure enough and, if not, adjust the pressure to prevent the fruit from falling.
Tests were successful, and also showed that the robotic hand’s sensors are capable of predicting the shape of a fruit with nearly 100% accuracy. The current prototype weighs just under 65 grams (2.29 oz), opens and closes in less than two seconds, and can lift objects weighing up to 1 kg (2.2 lb).
In the near future, the research team plans to enter the global market with this technology.
“For commercial deployment, we are currently developing a more scalable version of the gripper, with the goal of field deployment over the next two to four years,” says lead scientist Anand Mishra, who is an assistant professor in the Department of Mechanical, Materials and Aerospace Engineering at WVU.
The researchers also hope the robotic hand will find applications far beyond agriculture. Similar soft robotic systems could be used in space missions, underwater exploration, and healthcare.
A paper on the study was recently published in the journal Nature Communications.
Source: West Virginia University
