December 10, 2021

Why We Invested in ESTAT- A clutch that changes the game of mechanical motion

Leo Liu

The Mobile Robots Market

Multiple industries have shown high adoption of mobile robots to improve productivity and efficiency. This trend looks even more promising as the current mobile robotics market expects to grow from $19 billion in 2018 to potentially $54 billion by 2023. However, some existing problems are challenging for engineers and companies to scale up their products in a cost-effective way.

With 84% of the exoskeleton's total cost going to hardware, it creates difficulties for most applications that companies try to access. Clutches in robot joints are essential for most functionality, particularly for robots specializing in control and mobilization. However, these joints can cost up to a couple of thousand dollars each. By having enough joints for a mobile robot to function correctly, it will be a fortune to produce a single robot.  

Safety is another challenge that robotic engineers often run into. As the top priority in robot design, utilizing light-weighted hardware can ensure robots’ safety and responsiveness in operations. However, it is difficult for the current hardware to support dynamic movement in a lightweight package. As a result, most robots need to weigh a few hundred pounds to support their mobility.

ESTAT’s Unique Solution

Robots’ clutches utilized an electromagnetic field to create forces in the conventional method. Using a solenoid coil to activate/deactivate the clutch, the robot joint naturally becomes a heavy component (since coils are made from metal). On top of that, the conventional method requires a consistent current flow to create adherence within the clutch. This method could lead to overheating and other issues that are not ideal for customers. ESTAT spotted these problems and addressed them with a newly developed clutch that makes exoskeletons lighter and more energy-efficient.


ESTAT’s clutch composites films with an electrode and direct coding. The clutch has a positive charge on one side and a negative charge on the other. Placing two films with dielectric sides facing one another will create electrostatic adhesion. A notable part of this design is that the films are about the thickness of a piece of paper, and this size allows the clutch to fit in all kinds of applications. Compared to conventional clutches, ESTAT’s clutches are three times lighter in weight. The reduction in weight means that not only is it safer for robots to operate, but it will also significantly reduce the hardware cost without hundreds of pounds of hardware supporting those joints. 

Besides being lighter in weight, the clutch also supports the bi-directional operation with significantly less power consumption. ESTAT’s clutch also reduces power consumption to 600 times lower than conventional clutches. During one of ESTAT’s demos, an engineer controls the clutch’s adherence by applying a voltage across the two electrodes, which transmits forces up to 30lbs (clutch weights 20g) and maintains a stable connection within the clutch. The voltage-driven clutch can operate with only a small amount of current with less heat generation. Overall, the voltage-driven clutch shows tremendous upsides compared to the current-driven clutch. ESTAT offers a unique way to solve industry problems by utilizing electrostatics within the clutch and making robots more efficient in a lightweight package.


TSVC’s Insights

TSVC has always paid close attention to the robot industry as it shows tremendous potential in automation and other assistance operations. Through hardware and software, robots have unique capabilities to carry out various functions and promote work efficiencies across multiple industries. However, despite decades of development, overweight and overheating have always been significant challenges in robot production. The underlying safety issue from these challenges is one of TSVC’s concerns regarding the mobile robot industry. With more than 25 years of robotics hardware experience and multiple startups experiences, ESTAT’s founding team was well aware of these inefficiencies in robot production. With a team of talented engineers and credible advisors from Carnegie Mellon University, Stuart Diller, Co-founder/CEO of ESTAT, was able to bring a unique clutch to overcome these challenges. TSVC's general partner, Charles shared his thoughts on ESTAT: “There is a market need for ESTAT's robot actuator. With materials innovation, ESTAT's clutch brings dynamic movement in the joint without heavy parts and excessive energy. We believe these advantages are critical to ESTAT's future success.”



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