Smallest ingestible temperature sensor. Image credit: Dr Saransh Sharma.
Tiny electronic devices that travel through the gastrointestinal tract could one day do more than monitor the body’s internal conditions. By combining continuous sensing with targeted electrical stimulation, these devices could help deliver treatments when and where they are needed, paving the way for more responsive and personalised healthcare.
Dr Saransh Sharma of the University of Cambridge explored this emerging field in his recent lecture, “Closed-Loop Bioelectronics: From Sensing to Therapy”, delivered as part of the QAMSS Advanced Technology Lecture Series at the Cambridge Graphene Centre. He presented his group’s work on ingestible bioelectronic systems, highlighting how advances in miniaturised electronics are bringing sensing and therapeutic intervention closer together.
Miniaturised electronics for monitoring inside the body
Developing devices that can operate inside the body presents significant engineering challenges. They must be small and energy-efficient while retaining the ability to measure physiological signals, communicate wirelessly and, where necessary, deliver treatment.
Dr Sharma outlined three developments illustrating this progression. The first uses magnetic-field gradients and miniaturised ingestible devices to track their position in three dimensions in real time, providing information about where a device is as it moves through the gastrointestinal tract.
He then described a highly miniaturised temperature sensor built around a 1 mm² complementary metal–oxide–semiconductor (CMOS) integrated circuit consuming just 10 nanowatts of power. Incorporated into a device measuring only 6 mm in diameter, the sensor demonstrated precise, continuous monitoring of internal temperature.
The third system takes the technology a step further, combining programmable high-voltage electrical stimulation, pH-based targeting and custom CMOS electronics to influence the body’s natural hormone signalling. Together, these examples demonstrate how ingestible devices could evolve from diagnostic tools into systems capable of responding to physiological conditions.
Building bioelectronics that respond to the body
Moving from monitoring to treatment requires more than collecting accurate measurements. As Dr Sharma explained, “The challenge is not simply to sense a physiological signal, but to understand what that signal means, where it originates, and what action should follow.”
Biological processes change over time and vary between individuals, making it difficult to design systems that respond appropriately in every situation. He continued, “Effective closed-loop therapy must combine reliable sensing with accurate interpretation, precise targeting and the ability to adapt treatment as physiology changes, all while operating within strict limits on size, power consumption and wireless communication.”
Looking ahead, Dr Sharma sees miniaturisation as a route to monitoring and treating areas of the body that have traditionally been difficult to access continuously. “By combining sensing, computation and therapy, future bioelectronic devices could move beyond taking occasional measurements or delivering fixed treatments towards continuously understanding physiological state and responding when and where intervention is needed.”
The long-term goal is to integrate these capabilities into closed-loop platforms that can assess the body’s condition, determine when intervention is appropriate and adjust treatment accordingly. Such systems could ultimately support more personalised and adaptive approaches to disease monitoring and therapy.
About the speaker
Dr Saransh Sharma, University of Cambridge
Dr Saransh Sharma is an assistant professor in bioelectronic systems in the Department of Engineering (Electrical Engineering Division) at the University of Cambridge. He received the MS and PhD degrees in electrical engineering from the California Institute of Technology (Caltech), and the BTech degree in electronics and electrical communication engineering from the Indian Institute of Technology (IIT) Kharagpur. Prior to joining Cambridge in 2026, he completed postdoctoral research at the Massachusetts Institute of Technology (MIT).
Dr Sharma’s research lies at the intersection of electrical and biomedical engineering, with a focus on the design of highly miniaturized and ultra-low-power bioelectronic systems for healthcare applications. His laboratory develops custom complementary metal–oxide–semiconductor (CMOS) integrated circuits and systems, emphasising analog and mixed-signal design to enable new classes of ingestible, implantable and wearable medical devices.
His work has been recognised through numerous awards and honours, including the Wilts Prize and the Demetriades-Tsafka-Kokkalis Award for an outstanding PhD thesis at Caltech, Lewis Winner Award for an outstanding paper at ISSCC 2024, Best Student Paper Award at CICC 2025, Charles Lee Powell Fellowship at Caltech and Excellence in Mentorship Award at Caltech for mentoring undergraduate and graduate students.
By Dr Karen Steward