“We’re not going to be using iPhones in 10 years,” Jon Callaghan says flatly. For a venture capitalist whose firm, True Ventures, has turned improbable hardware bets like Fitbit, Ring, and Peloton into billion-dollar successes, this is not casual futurism it’s a thesis backed by capital, conviction, and a track record of spotting interface shifts before they hit the mainstream.
Callaghan’s argument is rooted in a fundamental critique: smartphones are inefficient intermediaries between humans and intelligence. Pulling a device from a pocket, unlocking it, navigating to an app, and typing or swiping is a clumsy ritual compared to what emerging technologies promise. Touchscreens, while revolutionary in their time, are now a bottleneck. As AI becomes the dominant layer in digital interaction, the friction of current smartphone workflows becomes glaring.
True Ventures is investing in alternatives that prioritize allowing new behaviors over simply delivering new gadgets. That philosophy betting on behavioral transformation rather than incremental hardware upgrades led the firm to its latest investment: Sandbar’s voice-activated smart ring. Worn on the index finger, the device functions as a sort of “thought companion,” designed for rapid, discreet capture of ideas through voice notes. In contrast with generalized AI wearables such as the Humane AI Pin, Sandbar focuses on a single, deeply human need: preserving fleeting thoughts without disrupting the moment.
The Sandbar ring works in conjunction with an iOS app and uses AI to transcribe and organize notes in a conversational UI. One of its unique features is the “Inner Voice” capability, which uses the wearer’s own speech patterns when reading notes aloud, thus giving the user the feeling of cognitive extension rather than talking to a synthetic assistant. It vibrates when the microphone is active, and captures audio only within personal range-the idea being to address privacy concerns.
That pedigree is reflected in this approach. Mina Fahmi and Kirak Hong previously collaborated at CTRL-Labs, the neural interface startup acquired by Meta back in 2019. CTRL-Labs had made its breakthrough in decoding motor neuron signals from the arm (in other words, electromyography, or EMG) to control computers and devices without the need for traditional input methods. It could understand the intent to move rather than just the actual movement, thus enabling applications that ranged from gaming to neurorehabilitation. By eschewing invasive brain implants and instead tapping into the spinal cord’s “low-hanging fruit” of neural signals, CTRL-Labs showed the world that wearable interfaces could merge human intent with machine execution seamlessly.
The lineage of the Sandbar ring from neural interface research underlines a preoccupation with natural, low-friction interaction. Whereas voice note capture and chatbot access have been devised on other AI rings, such as the Pebble Index and Wizpr Ring, respectively, the point of difference driven home by Sandbar is one of cognitive augmentation rather than conversational companionship. It is never listening, eschews wake words, and is engineered for whisper-level input making it viable in contexts where pulling out a phone or speaking aloud would be intrusive.
Market signals support Callaghan’s thesis. While the global smartphone market is saturated, growing at barely 2% annually, wearables-smartwatches, rings, and voice-enabled devices-are expanding at double-digit rates. In parallel, neural interfaces, augmented reality contact lenses, and multimodal AI-powered mixed reality headsets are rapidly improving, each chipping away at the smartphone’s role as the primary gateway to digital interaction. The convergence of these technologies points toward a post-smartphone ecosystem where input will be multimodal, context-aware, and embedded in the flow of daily life.
For investors and founders, the opportunity lies in the application layer interfaces that enable behaviors that people will soon find indispensable. As Callaghan says, “It’s about the behavior it enables that we will very soon realize we can’t live without.” Sandbar’s ring may seem niche today; Fitbit’s step tracking and Peloton’s connected cycling did once too. The core wager is that the next billion-dollar hardware interface will feel less like a device, more like an extension of human thought and action.
True Ventures’ disciplined capital strategy-seed checks of $3-6 million for 15-20% ownership-positions it to back these early behavioral shifts without chasing the hyperscaler-driven infrastructure boom. Yes, the projected CapEx for data centers and chips, some $5 trillion, is fuel for AI’s backend. But the front-end revolution will be won by whoever can design an interface that dissolves the boundary between what a human intends and a machine responds with. In that race, the smartphone is already falling behind.”
