Andrew says the book Contact Mechanics, by K.L. Johnson, has guided his career since he earned his PhD from the Massachusetts Institute of Technology in 2001. “I love this field,” he says of the engineering discipline. “It’s rigorous enough that you can examine the finest mathematical details of one body interacting with another, to generate new methods of testing materials, structures, or even internal organs just by ‘poking’ them. On the other hand, it’s accessible enough that any student can use it when considering friction, impact, machining, finger grip, or even buttons.”

Andrew likes hovercrafts. “I bought this toy,” he says. “It doesn’t work well at all, though, so we started a capstone project to make a better one.” Now, he says, he’s hoping to start a hovercraft racing league on campus.

“I’m pretty sure this sign is the oldest thing I own,” Andrew says. His brother made it for him when he got his own room, when he was 8 and his brother was 9. Why? “Just because,” Andrew says. “Anyone who knows me knows I’m a huge fan of ‘Just because.’ Fun fact: the sign still has some crispy bits of a now more than 30-year-old blue tack on it.

Andrew says the toy reminds him of two things. One is that animated TV shows helped him strengthen his attention span when he was a boy. “How many of us remember five-part, 30-minute episodes of series that were broadcast at 3 p.m. on weekdays, or going back further, the phrase, ‘Tune in next week?’ That is how you teach kids to pay attention.” The other is that a few of his students started a club called NU Toys to repair and modify old toys, including Voltron, whose rotating parts didn’t move anymore after decades of use.

Andrew signs all his emails “AG :)”—a moniker that his mentor Sanjay Sampath gave him at his first faculty position at Stony Brook University. Andrew says his Northeastern colleague Marilyn Minus wanted to help him understand his influence on his own students, so she enlisted several of his former pupils to write some kind words about him that were later printed on this aluminum board. “I keep it in my office, right in front of my face, as a reminder of the extreme privilege it is to be a university faculty member at Northeastern,” Andrew says. “Our students are some of the brightest, most diligent, and most considerate folks on the planet—each individual with the potential for an awesome future—and they listen to us. That responsibility is why I come to work every day—and also why I drink way too much coffee.”