The accurate monitoring of vital physiological parameters, exemplified by heart rate, respiratory rate, and intracranial pressure (ICP), is of paramount importance, particularly for managing severe cranial injuries. Despite the rapid development of implantable ICP sensing systems over the past decades, they still suffer from, for example, wire connection, low sensitivity, poor resolution, and the inability to monitor multiple variables simultaneously. Here, we propose an ultrasensitive multimodal biotelemetric system that amalgamates an iontronic pressure transducer with exceptional point (EP) operation for the monitoring of ICP signals. The proposed system can exhibit extraordinary performance regarding the detection of minuscule ICP fluctuation, demonstrated by the sensitivity of 115.95 kHz/mmHg and the sensing resolution down to 0.003 mmHg. Our system excels not only in the accurate quantification of ICP levels but also in distinguishing respiration and cardiac activities from ICP signals, thereby achieving the multimodal monitoring of ICP, respiratory, and heart rates within a single system. Our work may provide a pragmatic avenue for the real-time wireless monitoring of ICP and thus hold great potential to be extended to the monitoring of other vital physiological indicators.

Organic piezoelectric materials have attracted significant interest for applications in sensing, energy harvesting, and flexible electronics. However, its piezoelectric properties are yet to be improved. This study introduces a facile strategy to fabricate homogenous and dense polyvinylidene fluoride (PVDF) films with high piezoelectric performance via anhydrous CaCl₂ doping. The strong ion–dipole interaction between Ca²⁺ and F atoms, along with directional dipole alignment under an electric field at elevated temperature, as verified by molecular dynamics simulations and material characterizations. This results in an impressive β-phase content of 92.78% and a piezoelectric coefficient of 29.26 pm/V. A piezoelectric device fabricated from this PVDF film delivers an output voltage exceeding 12 V under external pressure and maintains stability over 60,000 cycles. When integrated with an LC resonant circuit, it functions as a wireless sensor for real-time motion monitoring. This scalable approach significantly advances piezoelectric polymer performance for practical applications.

Few‐layer nanosheets (NSs) of hexagonal boron nitride (h‐BN) and molybdenum disulfide (MoS₂) display notable piezoelectric properties. Yet, their integration into polymers typically yields non‐piezoelectric composites due to NSs' random distribution. We introduce a facile method for fabricating intrinsic piezoelectric composites incorporated with NSs without electric poling. Our innovative process aligns NSs within polyvinyl alcohol polymer, leveraging ice‐water interfacial tension, water crystallization thrust, and directional cross‐linking during freezing. The resulting PE composites exhibit a maximum piezoelectric coefficient of up to 25.5–28.4 pC N⁻¹, comparable to polyvinylidene difluoride (PVDF), with significant cost‐efficiency, safety, and scalability advantages over conventional materials. Using this composite, we develop highly sensitive wearable pressure and strain sensors, and an ultrasound energy harvester. These sensors detect finger bending and differentiate between walking and running, while the harvester generates ~1.18 V/2.31 μA under 1 W cm⁻² ultrasound input underwater. This universal method offers a novel manufacturing technique for piezoelectric composites, demonstrating remarkable effectiveness in synthesizing intrinsic piezoelectric composites based on 2D materials. Moreover, its potential extends to applications in wearable electronics and energy harvesting, promising significant advancements in these fields.