It's always intriguing to think about what new technologies the future will bring. But what you might not realize is that many of the building blocks of tomorrow are already in place. And lucky for us, most of the companies providing those blocks are publicly traded.

So, we asked three top Motley Fool investors to each discuss a company that they believe is building the word of tomorrow. Read on to see why they chose iRobot (NASDAQ:IRBT), Tesla (NASDAQ:TSLA), and Intuitive Surgical (NASDAQ:ISRG).

Roomba 960 robot cleaning a carpet with a child laying in the background

IMAGE SOURCE: IROBOT.

Let the robots do the work

Steve Symington (iRobot): It seems only fitting to include home robotics specialist iRobot in this mix. The company is already demonstrating its disruptive chops; iRobot's entry-level Roomba was the No. 1-selling vacuum based on total retail dollars spent in the United States last year -- and not just among robotic vacuums, but all vacuum cleaners, including upright models. 

iRobot is showing no signs of slowing down, either. Just last week, the home robotics specialist announced that second-quarter 2017 revenue climbed a better-than-expected 23% year over year to $183.1 million, including 46.4% year-over-year growth in U.S. consumer revenue to $97.3 million. The company also just launched its high-end Roomba 900-series robots in China in Q2, while at the same time introducing its lower-cost Roomba 890 and 690 Wi-Fi connected models in the U.S., EMEA, and China.

If you're worried about iRobot's over-reliance on the Roomba, have no fear. Sales of iRobot's wet floor care Braava and Braava jet models are on track to grow in the high-teens percent range this year, with particular strength following their recent introductions in Asia, where hardwood floors are more prominent. 

Looking toward the longer term, iRobot is also in the early stages of designing its own robotic lawn mower. And with the advent of visual mapping technology in its latest Roomba models, the company believes it has the opportunity to leverage its business to build a presence in other markets, like home security.

Perhaps unsurprisingly, iRobot is on an absolute tear with the value of its shares having nearly tripled over the past year, including a more than 80% gain so far in 2017 as of this writing. If iRobot is able to sustain its momentum and continue disrupting new industries with innovative robotics going forward, I see no reason its stock won't follow suit.

Building a new way to produce, store, and use energy

A Tesla car on a highway

Image source: Tesla.

Matt DiLallo (Tesla): In 2003, Tesla started out on a quest to develop the automobile of tomorrow by creating what would become not only a high-performance, zero-emission vehicle, but one of the safest cars ever built. The company has continued its evolution in recent years by taking a holistic approach to changing the way the world generates and uses energy by developing solutions to more efficiently produce, store, and use power. Tesla believes that this integrated effort will enable it to accelerate the world's transition away from fossil fuels.

One of the drivers of the company's efforts is its Gigafactory, which is the world's leading battery production factory. The facility's aim is to keep production costs down by maintaining a high level of efficiency, enabling it to support both a high-volume vehicle program as well as energy storage and solar products. In doing so, the company can offer an end-to-end solution to customers who can generate electricity from solar on their rooftops, store that energy in their Powerwalls, and then use it to power their homes and Teslas.

Tesla is just starting to hit its stride. With the launch of its first mass market vehicle, the Model 3, Tesla hopes to produce 10,000 vehicles per week at some point next year. That's a big step for a company that made just over 25,000 vehicles last quarter. Meanwhile, the company recently began manufacturing its new Solar Roof tiles and is starting to make inroads in the commercial power sector, having deployed a microgrid in Hawaii, for example, that combines solar power generation with storage capacity to provide continuous renewable power. These initiatives will help the company continue pressing on toward its goal of building a world that could one day be free from its addiction to fossil fuels.

It isn't complicated

Cory Renauer (Intuitive Surgical, Inc.): It's hard to say what American healthcare will look like in the years ahead, but it's safe to assume that healthcare providers will always be motivated to reduce surgical complications. Using robotic assistance to perform standard procedures with smaller incisions are already helping today's surgeons boost safety and reduce recovery times in the present. A recent study showed repairing hernias with minimally invasive techniques instead of open surgery significantly lowers the risk of infections, and length of hospital stays. Another hospital in Montreal claims the introduction of da Vinci systems has lowered in-patient board costs by about $5,000 per patient.

Surgeons sitting behind one of this company's da Vinci surgical systems have ultra-precise control of tiny instruments and magnified 3D vision that makes hand-held scalpels seem as crude as a rusty saw blade by candlelight. The variety of standard procedures Intuitive Surgical's surgical systems are capable of performing is still somewhat limited, but it's larger than any of its competitors -- and expanding.

In total, 752,000 procedures were performed with the company's systems last year, and the company expects that figure to rise between 12% and 14% higher this year. As the variety of procedures grows, each installed system becomes more valuable to the hospitals that own them and generate more revenue for Intuitive Surgical. The company currently generates about $1,840 in sales of the instruments and accessories that must be replaced after each surgery.

Adoption rates within hernia repair and other standard procedures are probably low enough to fuel impressive growth for years to come. If da Vinci systems continue becoming more versatile, though, this stock could bring your nest egg of tomorrow to colossal proportions.

Cory Renauer has no position in any stocks mentioned. Matt DiLallo owns shares of Intuitive Surgical and iRobot. Steve Symington owns shares of iRobot. The Motley Fool owns shares of and recommends Intuitive Surgical, iRobot, and Tesla. The Motley Fool has a disclosure policy.