An innovation that strikes a chord
In the Center for Engineering Innovation and Design (CEID), Eytan Israel '26 sings “Hey There Delilah,” a song by the Plain White T’s, while accompanying himself on acoustic guitar. His right hand does the strumming, and a device attached to the fret board forms the song’s chords.
Israel calls it the AllStrum Guitar, the second product of his startup AllStrum. He got the idea for the project a few years ago when he was a counselor at a camp for children with special needs. Several campers loved music and wanted to make their own, but didn’t have the fine motor skills to hold down a pattern of chords to play a song. He then developed the AllStrum Ukulele, a programmable device that holds down chords automatically.
“The user doesn’t need to know the chords to have the experience of making music,” said Israel, who's majoring in electrical engineering and computer science. “It was incredible to visit different communities and watch individuals with special needs and physical disabilities play just by strumming. The feedback I got was very positive. Individuals felt empowered and had huge smiles on their faces.”
But many who tried it out told him that if he could adapt it to guitar, his innovation would reach an even wider audience. So Israel got to work. He soon realized that developing the device for the six-string guitar was significantly more complex than his work on the one for the four-string ukulele.
He described some of the engineering challenges behind the camshaft system that presses the chords. “On the ukulele, the chords are simple enough that each fret only needed three possible cam-lobe orientations to produce the most common chords. The guitar was much more complicated. I quickly realized the camshafts couldn’t run across the frets like they do on the ukulele. Instead, they had to run along the strings. That created another constraint: the motors are too large to sit directly next to each other along the neck. To solve this, I placed three motors on each side of the neck and staggered them at different heights. I also offset the pushers onto slightly different axes so the mechanisms wouldn’t collide with each other.”
Offering some guidance, Larry Wilen, senior research scientist at the CEID, advised Israel to simply focus on the first fret. “Once I mastered that, I was able to pretty rapidly extend the design to more frets.”
Soon, he managed to complete the work with mentoring from Wilen, and finally presented it to Professor Rajit Manohar, the director of undergraduate studies for electrical engineering and computer science. Israel created an iOS Bluetooth app for the device, so that users can select and play any of their favorite songs. He also worked on all of the embedded systems, microcontroller programming, wireless communication, and the battery management system. Except for the motors and ball bearings, Israel made everything with 3D printing.
The project has received three grants from the Tsai Center for Innovative Thinking at Yale (Tsai CITY). Along with his new co-founder Matthew Mendelsohn (YC ‘27), who has joined as chief operating officer for the venture, AllStrum was selected as one of four finalists for the Startup Yale Rothberg Catalyzer Prize in April. The AllStrum Ukulele and Guitar are patent pending, and Eytan and Mendelsohn are hoping to roll them out to users soon. Their website (www.allstrum.com) displays demos of Yale students and also people with special needs using their device.
"I really hope to be able to open up music to anyone who isn’t able to play by themselves, from individuals with physical and mental disabilities to children who need some guitar training wheels to anyone who doesn’t have enough time to fully learn how to play – a student, for instance, or a working parent.”
L-R: Manohar, Wilen, and Israel in the Center for Engineering Innovation & Design.
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Published Date
Mar 19, 2026
