Advances in robotic technology are making it possible for retail businesses to complete more complex tasks at higher speeds and with improved control and outcomes, driving deal activity in the sector, as we discover in the fourth part of Mergers & Acquistions’ 7-part series, Retail Tech M&A. Robots assist with sorting and packing consumer goods. Here's our look at robots:

The world’s largest retailer will add shelf-scanning robots to 650 more U.S. stores by the end of the summer, bringing its fleet to 1,000. The six-foot-tall Bossa Nova devices, equipped with 15 cameras each, roam aisles and send alerts to store employees’ handheld devices when items are out of stock, helping to solve a vexing problem that costs retailers nearly a trillion dollars annually, according to researcher IHL Group. The new robots, designed by San Francisco-based Bossa Nova Robotics Inc., join the ranks of Walmart’s increasingly automated workforce which also includes devices to scrub floors, unload trucks and gather online-grocery orders. Walmart expands robotic workforce to 650 additional stores.

E-commerce company Shopify Inc. (NYSE: SHOP) acquired 6 River Systems for $450 million. 6 River Systems uses cloud-based software and mobile robots called “Chuck” that assist employees with inventory replenishment, picking, sorting and packing. The acquisition adds a fleet of six Chuck robots to Shopify, while it allows 6 River to expand its robot technology business. Shopify is keeping the 6 River brand.

“Together, we will help thousands of businesses improve their fulfillment operations with an easy-to-learn solution that can more than double productivity and improve accuracy,” says 6 River CEO Jerome Dubois.

Thomas H. Lee Partners
TH Lee is buying a majority stake in robot technology company AutoStore from EQT, an investment and PE firm. EQT is keeping a 10 percent stake in AutoStore through a reinvestment.

AutoStore makes robots that retrieve products in warehouses to increase efficiency, and to cater to consumer demands to get deliveries faster. AutoStore, based in Norway, operates more than 11,000 robots in 28 countries. The deal will help expand AutoStore’s technology and software systems.

“Global megatrends, including increasing focus on automation and robotization, urbanization and need for space efficient solutions, as well as e-commerce demands requiring increased speed and accuracy, are all expected to continue to fuel AutoStore’s growth globally,” AutoStore adds in a release.

The robotics sector is attracting buyers outside the U.S. also. Japanese technology company Hitachi is buying robots manufacturer JR Automation Technologies from PE firm Crestview Partners for about $1.4 billion.

JR Automation builds production lines and logistics systems that deploy industrial robots for the consumer and food and beverage industries. The acquisition expands Hitachi’s presence in the U.S. robotics industry.

“In the manufacturing and logistics fields, there has been a growing demand for automation because of decreased working age populations, intensifying global competition, and further quality improvement requirements to prevent significant product recalls,” according to a Hitachi release.

With the holiday shopping season in full swing, all eyes are on the retail industry, which is undergoing transformational changes. Mergers & Acquisitions' series examines the impact of 7 technologies on M&A in the retail sector. Read the whole series:

Retail Tech M&A #1: Nike, McDonald's, PayPal, add customization, IoT
Retail Tech M&A #2: Why Walmart and other retailers are buying artificial intelligence startups
Retail Tech M&A #3: Amazon leads race to build fulfillment centers
Retail Tech M&A #4: Do robots fill orders faster?
Retail Tech M&A #5: Voice recognition gives retailers more ways to communicate
Retail Tech M&A #6: Data improves customer service
Retail Tech M&A #7: Demand for convenience drives growth in mobile ordering

We'll continue watching how these technologies and trends play out in the M&A in the new year.